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Biomedical subjects

Jie Chen

Publications and source records attributed to Jie Chen.

At least 91 records · Page 5Linked to original sources
PubMed2006

[Determination of anabolic steroid hormones in animal muscle tissues by gas chromatography/mass spectrometry].

A gas chromatography/mass spectrometry (GC/MS) method was developed for the determination of multi-residues of steroid anabolic hormones epitestosterone (ETS), testosterone 17-propionate (PTS), nandrolone (17beta-NT), 17alpha-methyltestosterone (MTS), 17beta-estradiol (17beta-ES), estriol ( EST), 17alpha-ethinylestradiol (EES), estrone (ESN) and 17beta-estradiol 3-benzoate (BES) in the muscle tissues of various animal species. Homogenized tissue samples were enzymatically digested in acetate buffer (pH 5.0). Consequently, methanol was added and the mixtures were extracted under ultrasonication incubation. Clean-up was carried out for at least two times with methyl tert-butyl ether (MTBE) liquid-liquid partitioning followed by a reversed-phase solid phase extraction (SPE) cartridge purification. The eluate with methanol was evaporated to dryness by N2 at 40 degrees C and derivatization was achieved with N-methyl-N-( trimethylsilyl) trifluoroacetamide/iodotrimethylsilane/dithioerythritol (MSTFA-TMIS-DTE) at 60 degrees C for 45 min. The reaction mixture was injected into a gas chromatograph with a DB-1 capillary column coupled with a mass spectrometer. The samples were tested by different selected ion monitoring modes with electron impact (EI) source for the androgens and estrogens. The limits of quantitation (LOQ) for the above 9 hormones were in the range of 1.0 - 2.0 microg/kg. At the 2.0 microg/kg LOQ spiked level, the mean recoveries were within 62.5% - 80.5%, and the relative standard deviations were within 12.5% - 26.8%. The real sample tests showed this method can be used for the sensitive and accurate determination of multi-steroid anabolic hormones residues in biological muscle samples.

Acetamides↗
PubMed2006

[Controlled study on treatment of cervical spondylopathy of the nerve root type with acupuncture, moxibustion and massage as main].

OBJECTIVE: To probe into clinical value of comprehensive program of acupuncture, moxibustion and massage as main for treatment of cervical spondylopathy of the nerve root type. METHODS: Five centers, single blind, randomized controlled method were used, 660 cases were divided into a treatment group of 317 cases and a control group of 311 cases. They were treated respectively with comprehensive program of acupuncture, moxibustion and massage as main, and comprehensive program of physical therapy as main. Establish syndrome detection scale and multiply dimensional effect assessment indexes, and evaluate the therapeutic effects and safety. RESULTS: The cured rate, the cured-markedly effective rate were 42.9%, 64.4% in the treatment group, respectively, better than 16.7%, 36.3% in the control group (P<0.01); after treatment of 2 weeks, clinical symptoms improved in the both groups, but the treatment group was better than the control group in the improvement degrees of neck-shoulder-limb pain, neck rigidity, abnormality of cervical anteflexion, etc. (P<0.01 or P<0.05); the treatment group was shorter than the control group in the time of producing the effect and therapeutic course (P<0.01). CONCLUSION: Comprehensive program of acupuncture, moxibustion and massage as main is safe and effective for treatment of cervical spondylopathy, with a better therapeutic effect compared with the comprehensive program of physical therapy.

Acupuncture Therapy↗
PubMed2006

[Expression of mouse CD1.1 in CHO cells and its stimulatory function on NKT cells].

AIM: To get cell lines which express mouse CD1.1 (mCD1.1) stably and to study the stimulatory effects of mCD1.1 on lymphocytes from many tissues. METHODS: The intestinal epithelial cells were isolated and their total RNA was prepared. By RT-PCR, the gene coding mCD1.1 was obtained and then cloned into the pcDNA3.1 vector through BamH I and EcoR I. The reconstructed plasmid, named pcDNA3.1-mCD1.1, was transfected into CHO cells by electroporation. The clones that grew well in the medium containing G418 were selected and their mCD1.1 expression was analyzed by RT-PCR and flow cytometry(FCM). The mCD1.1-expressing CHO cells were co-cultured with lymphocytes freshly isolated from the liver or mesenteric lymph nodes with or without LPS. The CHO cells were treated with mitomycin C to inhibit their proliferation. The lymphocyte proliferation was detected by MTT. In addition, the lymphocytes collected from the co-culture system were stained with fluorescein-labeled monoclonal antibodies against mouse NK1.1 and CD3. The double positive cells were detected by FCM. RESULTS: By RT-PCR, the gene coding mCD1.1 was acquired, identical to that reported by some authors with one base different from that reported by Genbank. Many clones that express mCD1.1 stably were obtained. MCD1.1-expressing CHO cells could stimulate lymphocytes to proliferate in the presence or absence of LPS and elevate the percentage of NK1.1 and CD3 double-positive cells. CONCLUSION: The mCD1.1 expressed on the membrane of CHO cells could stimulate the proliferation of NKT cells.

Animals↗
PubMed2006

[Role of Fas-FasL and caspase-3 signal transduction pathway in promoting apoptosis of T lymphocyte subset in SLE patients].

AIM: To explore the relationship between Fas-FasL-mediated signal transduction pathway and apoptosis disorder of T lymphocyte subset in SLE patients. METHODS: The expression rate of membrane Fas, FasL and that of intracellular activated caspase-3 of T lymphocyte subset were determined by flow cytometry. RESULTS: Compared with healthy control group, the expression rate of membrane Fas on CD4(+) T cells significantly increased in SLE patients in the active and inactive phases (P<0.05), however, that on CD8(+) T cells slightly increased but there was no statistical significance (P>0.05). The expression rate of FasL on T cell subset in SLE patients in the active and inactive phases significantly increased (P<0.05) but there was no obvious difference of the expression rate of Fas and FasL on T cell subset between the two disease groups (P>0.05). The expression rate of intracellular activated caspase-3 in T cell subset of SLE patients in the active phase was notably higher than that in the inactive phase and healthy control group (P<0.05). The expression rate of intracellular activated caspase-3 in T cell subset of SLE patients in the inactive phase was slightly higher than that in health control group but there was no statistical significance. CONCLUSION: Apoptotic speed of T lymphocyte subset in SLE patients was accelerated while CD4(+) T cells were in a state of active apoptosis. It is possible that Fas-FasL signal transduction pathway plays an important role in the induction of T cell apoptosis. The degree of apoptosis of T lymphocytes closely correlates with the disease's activity in SLE patients.

Adolescent↗
PubMed2006

Trichostatin A improves the anticancer activity of low concentrations of curcumin in human leukemia cells.

Curcumin (Cur), a promising anticancer drug, kills tumor cells through either diminishing or promoting reactive oxygen species (ROS) generation. In this study, it was investigated whether trichostatin A (TSA), a specific histone deacetylase (HDAC) inhibitor and a new anticancer drug, could improve the anticancer activity of low concentrations of Cur in human leukemia cells (HL-60). HL-60 cells were treated with Cur, TSA or their combinations; cell proliferation arrest, lactate dehydrogenase (LDH) release and cell viability were measured as indicators of cell damage. Reactive oxygen species (ROS) accumulation and the acetylation of histones were also measured. The cytotoxicity of Cur and TSA increased in a time and dose-dependent manner. Low Cur (no more than 20 microM) diminished the ROS generation in HL-60 cells, while high Cur (50 and 100 microM) promoted that. In contrast, TSA showed no influence on ROS generation. When their effects on histone acetylation were determined, low Cur showed no effect, while TSA significantly increased that. As expected, combinations of low Cur and TSA could not only diminish ROS generation, but also increase histone acetylation, and hence showed a more significant cytotoxicity in HL-60 cells. Since the extra ROS generation may also harm normal cells, instead of using high Cur, combining low Cur with TSA is obviously a better strategy to improve the anticancer activity of Cur.

Acetylation↗
PubMed2006

[Abscopal effect on metastatic tumor induced by oncolytic virus of H101 combining with local heating].

BACKGROUND & OBJECTIVE: The abscopal effect on the tumors is a distant antitumor activity induced by local treatments. The study was to observe the induction of abscopal effect by the combination of H101 oncolytic virotherapy with local heating. METHODS: Five patients with histologically confirmed, surgically unresectable metastatic malignant tumors (2 nasopharyngeal carcinomas, 1 pulmonary carcinoma, 1 parosteal sarcoma and 1 bladder carcinoma) that had definitely failed to the conventional chemotherapy and radiotherapy or refused these therapies were enrolled in this experimental therapy. All patients were treated with local intra tumor injection of H101 (5x10(11) - 15x10(11) VP) combined with 60-min heating at 42 degrees C. RESULTS: Two patients were cured with complete regressions of both injected and non-injected tumors and have survived for a long period up to date. Three patients responded to the novel therapy variously and eventually died from the disease, who survived 29, 15 and 13 months, respectively. CONCLUSION: The abscopal antitumor effect could be induced by the combination of H101 local intratumoral injection with heating.

Adenocarcinoma↗
PubMed2006

[Thyroid malignant tumor with flare up glottic paralysis for first symptom].

OBJECTIVE: To approach clinical feature of thyroid malignant tumor with Flare up glottic paralysis for first symptom, and analysis that should be avoided missed diagnosis and misdiagnosis during diagnosis and treatment. METHOD: Retrospective research five cases of thyroid malignant tumor with flare up glottic paralysis papillary adenocarcinoma of thyroid by pathology. Four cases had one side glottic paralysis, the same side thyroid were moved after dissecting the recurrent laryngeal nerve. Three cases of them recovered normal vocal cord function, the function of one case was compensated by another side vocal cord. The last one had right gliotic paralysis first, then both cricoarytenoid joint had been fixed, hoarse voice was worse and developed to dyspnea since the tumor invaded in larynx one year later. We only did cut the right thyroid and right half larynx, but the tumor came back again in larynx in three months, then had to removal whole larynx without recurrence follow up two years. CONCLUSION: For the flare up glottic paralysis with same side tiny thyroid tumor, we suggest that the thyroid must be made operation research if no other reasons, dissecting and protecting the recurrent laryngeal nerve during operation, and cut reasonable thyroid and others according to fast pathologic diagnosis.

Carcinoma, Papillary↗
PubMed2006

[Correlation analysis on the malocclusion and articulation of skeletal angle III malocclusion in mixed dentition].

OBJECTIVE: To investigate the effects of skeletal Class III malocclusion in mixed dentition on speech articulation and to look for which factors lead to the speech errors. METHODS: Thirty-eight children with skeletal Angle Ill malocclusion in mixed dentition were selected as a sample group and 40 children with normal occlusion in mixed dentition as a control group. Two phoneticians evaluated their articulations and wrote down error phonemes respectively. The correlation analysis was undertaken between the number of errors and the measurements of patients' cephalometry. RESULTS: The number of errors were correlated significantly with overbite, UI-LI, OBJ (OB+OJ) and TD-PW. CONCLUSION: There is articulatory malfunction in the majority of skeletal Angle III malocclusion patients in mixed dentition. Articulatory malfunction is related to the position of incisors and the tongue.

Cephalometry↗
PubMed2006

[Free anterolateral thigh flap for repairing the defects of oral cavity and maxillofacial].

OBJECTIVE: To investigate the outcomes following the tumor resection of oral cavity and maxillofacial and reconstruction with free anterolateral thigh flaps (ALT). METHODS: Thirty one patients underwent ALT reconstruction following the tumor resection from Dec. 2004 to Dec. 2005. Among them, 17 cases were squamous cell carcinoma (SCC) of tongue, 6 cases of buccal SCC and 8 other malignant. The size of the ALT flaps ranged from 4 to 8 cm in width and 6 to 23 cm in length. Tracheotomy were performed for 4 cases intraoperatively. RESULTS: The overall successful rate was 96.8%. Thirty cases survival no cancer, 1 case died of recurrent and no-controlled of lymph-node in 8 months after operation. Postoperative vessel thrombosis occurred in 3 flaps between 12 hours to 4 days after operation. Two of them were saved. The necrosis area of the third flap was 25%. CONCLUSIONS: The ALT was benefit to repair the defects of oral cavity and maxillofacial, and the donor place was more easily hidden and didn't not influence the outlook and function; the important normal functional framing such as teeth and bone should be preserved; the pedicle of vessel could't be twisted during the procedure of reconstruction to avoid vein oppressed; the size of flap should be suitable to defects in order to avoid flaps being crowd and blood clot; tracheotomy was safe while repairing the defect of hard and soft palate. Reconstructive surgical procedures;

Adult↗
PubMed2006

[Platelet and tissue factor: review].

It is generally accepted that tissue factor plays an important role in coagulation and intravascular thrombus formation. Tissue factor is not only found primarily on the surface of certain cells that are located outside the vasculature, but also found in circulating cells. Monocyte express tissue factor induced by endotoxin. Recently, many researches indicate that P-selectin, CD40 ligand and GPIIb/IIIa receptor of platelet can also affect expression of tissue factor by monocyters. In addition, a lot of studies showed that tissue factor exist in the circulation including contained platelet. Tissue factor in the platelet releases under certain condition, and initiates coagulation. In this review the relation between platelet and tissue factor was elaborated.

Blood Platelets↗
PubMed2006

[Knocking down osteopontin expression by specific siRNA reduces the in vitro invasiveness of human hepatocellular carcinoma cells].

OBJECTIVE: To study the effect of osteopontin (OPN) expression down-regulated by RNA interference (RNAi) on the invasiveness of hepatocelluar carcinoma cell line HCC-LM3. METHODS: HCC-LM3 cells were transfected with the chemically synthesized small interfering RNA (siRNA) formulated by lipofectamine 2000. Wild type HCC-LM3 and HCC-LM3 cells transfected with non-specific siRNA served as controls. Real-time PCR and Western blotting were used to quantify the mRNA and OPN protein levels. The malignant phenotypes of transfected HCC-LM3 cells including cellular growth rate, colony formation and Matrigel invasion activities were analyzed. RESULTS: Sequence-specific siRNAs targeting OPN suppressed OPN RNA expression by 79% and also decreased OPN protein level by 81% in HCC-LM3 cells. The number of formed colonies and migrating numbers in vitro were decreased in HCC-LM3 cells transfected using sequence-specific siRNAs targeting OPN relative to controls (P < 0.05). CONCLUSION: This study demonstrated that specific siRNA is able to reduce OPN at both the mRNA and protein levels and significantly diminishes the invasiveness of hepatocellular carcinoma cells.

Carcinoma, Hepatocellular↗
PubMed2006

[Determination of 3-monochloropropane-1,2-diol in hydrolyzed vegetable proteins and soy by solid phase extraction and gas chromatography/negative chemical ionization-mass spectrometry].

Solid phase extraction (SPE) and gas chromatographic/negative chemical ionization-mass spectrometric (GC/NCI-MS) method was developed for the determination of 3-monochloropropane-1,2-diol (3-MCPD) in hydrolyzed vegetable proteins (HVP) and soy. The optimized conditions for the extraction and cleanup of 3-MCPD on an Aoisa-HBL column were investigated. The extract with hexane-ethyl acetate was evaporated to nearly dry by N2 at 40 degrees C and derivatization was performed with 1-(heptafluorobutyryl) imidazole at 70 degrees C for 30 min. The mixture was then injected into a gas chromatograph with a DB-5MS capillary column, detected by a mass spectrometer in negative chemical ionization and selected ion monitoring mode (NCI/SIM) and quantified with external standard calibration. The limit of quantitation (LOQ) for 3-MCPD was 0.5 microg/kg. The average recovery was in a range of 92.2%-97.4% with a relative standard deviation range of 3.6%-10.9%. The results indicated that the method could be used for the sensitive and accurate determination of 3-MCPD in foods and agriculture products.

Gas Chromatography-Mass Spectrometry↗
PubMed2005

Adenovirus-mediated Ink4a/ARF gene transfer significantly suppressed the growth of pancreatic carcinoma cells.

OBJECTIVES: To determine the effects of adenovirus-mediated transfer of p14(ARF) and p16(INK4a) on growth and apoptosis of human pancreatic carcinoma cell lines. RESULTS: Pancreatic carcinoma cell lines, PC-7, PANC-1 and MIA PaCa-2 (p14(ARF)-/- and p16(INK4a)-/-), were used. PC-7 (p53 wt) and MIA PaCa-2 (p53 mt) cells infected with recombinant adenovirus vector expressing p14(ARF) gene (Adp14) showed significant inhibition of cell growth compared with control vector in vitro and in vivo, whereas PANC-1 cells (p53 mt) did not show such effects. Those three cell lines exhibited growth retardation and senescence phenotype after infected with the adenovirus vector containing p16(INK4a) gene (Adp16) in vivo and in vitro. CONCLUSIONS: Adenovirus-mediated transfer of p14(ARF) and p16(INK4a) produces significant growth suppression of pancreatic carcinoma cells in vitro and in vivo. The effects of Adp14 partly depend on the status of p53 gene in those cells.

Adenoviridae↗
PubMed2005

Preferential occupancy of histone variant H2AZ at inactive promoters influences local histone modifications and chromatin remodeling.

The yeast histone variant H2AZ (Htz1) is implicated in transcription activation, prevention of the ectopic spread of heterochromatin, and genome integrity. Our genome-wide localization analysis revealed that Htz1 is widely, but nonrandomly, distributed throughout the genome in an SWR1-dependent manner. We found that Htz1 is enriched in intergenic regions compared with coding regions. Its occupancy is inversely proportional to transcription rates and the enrichment of the RNA polymerase II under different growth conditions. However, Htz1 does not seem to directly regulate transcription repression genome-wide; instead, the presence of Htz1 under the inactivated condition is essential for optimal activation of a subset of genes. In addition, Htz1 is not generally responsible for nucleosome positioning, even at those promoters where Htz1 is highly enriched. Finally, using a biochemical approach, we demonstrate that incorporation of Htz1 into nucleosomes inhibits activities of histone modifiers associated with transcription, Dot1, Set2, and NuA4 and reduces the nucleosome mobilization driven by chromatin remodeling complexes. These lines of evidence collectively suggest that Htz1 may serve to mark quiescent promoters for proper activation.

Chromatin Assembly and Disassembly↗
PubMed2005

Identification of significant periodic genes in microarray gene expression data.

BACKGROUND: One frequent application of microarray experiments is in the study of monitoring gene activities in a cell during cell cycle or cell division. A new challenge for analyzing the microarray experiments is to identify genes that are statistically significantly periodically expressed during the cell cycle. Such a challenge occurs due to the large number of genes that are simultaneously measured, a moderate to small number of measurements per gene taken at different time points, and high levels of non-normal random noises inherited in the data. RESULTS: Based on two statistical hypothesis testing methods for identifying periodic time series, a novel statistical inference approach, the C&G procedure, is proposed to effectively screen out statistically significantly periodically expressed genes. The approach is then applied to yeast and bacterial cell cycle gene expression data sets, as well as to human fibroblasts and human cancer cell line data sets, and significantly periodically expressed genes are successfully identified. CONCLUSION: The C&G procedure proposed is an effective method for identifying statistically significant periodic genes in microarray time series gene expression data.

Algorithms↗
PubMed2005

Involvement of cAMP/cAMP-dependent protein kinase signaling pathway in regulation of Na+,K+-ATPase upon activation of opioid receptors by morphine.

The depolarization of neurons induced by impairment of Na+,K+-ATPase activity after long-term opiate treatment has been shown to involve the development of opioid dependence. However, the mechanisms underlying changes in Na+,K+-ATPase activity after opioid treatment are unclear. The best-established molecular adaptation to long-term opioid exposure is up-regulation of the cAMP/cAMP-dependent protein kinase (PKA) signaling pathway; this study, therefore, was undertaken to investigate the role of up-regulation of cAMP/PKA signaling pathway in alteration of the mouse hippocampal Na+,K+-ATPase activity. The results demonstrated that short-term morphine treatment dose dependently stimulated Na+,K+-ATPase activity. This action could be significantly suppressed by adenylyl cyclase activator 7beta-acetoxy-8,13-epoxy-1alpha,6beta,9alpha-trihydroxylabd-14-en-11-one (forskolin), or the cAMP analog dibutyryl-cAMP. Contrary to short-term morphine treatment, long-term treatment significantly inhibited Na+,K+-ATPase activity. Moreover, an additional decrease in Na+,K+-ATPase activity was observed by naloxone precipitation. The effects of both short- and long-term morphine treatment on Na+,K+-ATPase activity were naltrexone-reversible. The regulation of Na+,K+-ATPase activity by morphine was inversely correlated with intracellular cAMP accumulation. N-[2-(4-Bromocinnamylamino)ethyl]-5-isoquinoline (H89), a specific PKA inhibitor, mimicked the stimulatory effect of short-term morphine but antagonized the inhibitory effect of long-term morphine treatment on Na+,K+-ATPase activity. However, okadaic acid, a protein phosphatase inhibitor, suppressed short-term morphine stimulation but potentiated long-term morphine inhibition of Na+,K+-ATPase activity. The regulation of Na+,K+-ATPase activity by morphine treatment seemed to associate with the alteration in phosphorylation level but not to be relevant to the change in abundance of Na+,K+-ATPase. These findings strongly demonstrate that cAMP/PKA signaling pathway involves regulation of Na+,K+-ATPase activity after activation of opioid receptors.

Adenylyl Cyclases↗
PubMed2005

Detecting periodic patterns in unevenly spaced gene expression time series using Lomb-Scargle periodograms.

MOTIVATION: Periodic patterns in time series resulting from biological experiments are of great interest. The commonly used Fast Fourier Transform (FFT) algorithm is applicable only when data are evenly spaced and when no values are missing, which is not always the case in high-throughput measurements. The choice of statistic to evaluate the significance of the periodic patterns for unevenly spaced gene expression time series has not been well substantiated. METHODS: The Lomb-Scargle periodogram approach is used to search time series of gene expression to quantify the periodic behavior of every gene represented on the DNA array. The Lomb-Scargle periodogram analysis provides a direct method to treat missing values and unevenly spaced time points. We propose the combination of a Lomb-Scargle test statistic for periodicity and a multiple hypothesis testing procedure with controlled false discovery rate to detect significant periodic gene expression patterns. RESULTS: We analyzed the Plasmodium falciparum gene expression dataset. In the Quality Control Dataset of 5080 expression patterns, we found 4112 periodic probes. In addition, we identified 243 probes with periodic expression in the Complete Dataset, which could not be examined in the original study by the FFT analysis due to an excessive number of missing values. While most periodic genes had a period of 48 h, some had a period close to 24 h. Our approach should be applicable for detection and quantification of periodic patterns in any unevenly spaced gene expression time-series data.

Algorithms↗