Biomedical subjects

Tao Chen

Publications and source records attributed to Tao Chen.

At least 109 records · Page 6Linked to original sources

PubMed2004

[Meta-analysis of relationship between lymph node micrometastasis and prognosis in stage I non-small cell lung cancer patients].

BACKGROUND & OBJECTIVE: Lymph node metastasis is an important factor for prognosis of non-small cell lung cancer (NSCLC). There were different opinions about what effect does lymph node micrometastasis have on prognosis. This study was designed to collect literatures of lymph node micrometastasis and prognosis in stage I NSCLC patients, in order to investigate their relationship. METHODS: The results from eight literatures on lymph node micrometastasis and prognosis from 1980 to 2002 were analyzed synthetically by meta-analysis. The cumulative cases were 536 NSCLC patients with stage I disease. RESULTS: The detection rate of lymph node micrometastasis ranged from 3.4% to 28.9%, and the rate of positive cases ranged from 20% to 70%. The 3-, 5-year over-survival rate for positive lymph node micrometastasis patients was worse than those of negative lymph node micrometastasis patients: odd ratios (ORs) were 4.16 (95%CI:2.32-7.46) and 3.57 (95%CI:2.30-5.53), respectively (P< 0.01). CONCLUSION: Positive lymph node micrometastasis may be an adverse factor for post-operative prognosis of NSCLC stage I patients.

Carcinoma, Non-Small-Cell Lung↗

PubMed2004

[Determination of serum acute phase reaction protein in patients with severe acute respiratory syndrome].

OBJECTIVE: To study the diagnostic value of determinations of serum acute phase reaction protein, such as complement 3 (C3), complement 4 (C4), prealbumin (PA) and C-reactive protein (CRP), etc., in patients with severe acute respiratory syndrome (SARS). METHODS: Serum levels of C3, C4, PA and CRP were determined by turbidimetry in 54 cases of SARS, 20 of other pneumonia and 30 normal persons. RESULTS: Serum concentrations of C3, C4, CRP and PA were (1.18 +/- 0.42) g/L, (1.15 +/- 0.56) g/L, (10.52 +/- 8.77) mg/L and (107 +/- 54) mg/L in SARS patients, (1.30 +/- 0.46) g/L, (0.57 +/- 0.31) g/L, (0.88 +/- 0.43) mg/L and (291 +/- 76) mg/L in patients with other pneumonia, and (1.11 +/- 0.56) g/L, (0.38 +/- 0.26) g/L, (0.42 +/- 0.26) mg/L and (376 +/- 74) mg/L in normal persons, respectively. Serum level of PA was significantly lower and levels of C4 and CRP significantly in patients with SARS higher than those in patients with other pneumonia and normal persons (P < 0.01). There was no significant difference in serum level of C3 between the three groups (P > 0.05). CONCLUSION: Determination of serum level of C4, CRP and PA in suspected patients is beneficial to early differential diagnosis for SARS.

Acute-Phase Proteins↗

PubMed2004

[The application of p53 gene mutation status in fecal specimen in the diagnosis of colorectal carcinoma].

OBJECTIVE: To explore the value of analysis of p53 gene mutation in fecal specimen in the diagnosis of colorectal carcinoma (CRC) in order to establish a non-invasive method for the screening of CRC. METHODS: The status of p53 gene mutation of the tumor tissues and corresponding fecal specimens was analyzed by polymerase chain reaction-single strand configuration polymorphism with EB staining in 40 CRC, 20 colorectal adenoma and 15 gastrocarcinoma. RESULTS: Amplification rates of fecal p53 gene were 90%, 85% and 93% in 40 CRC, 20 colorectal adenoma and 15 gastrocarcinoma, respectively. Total amplification rate was 89%. p53 gene mutation in tumor tissue was detected in 29 of 40 cases of CRC, 23 cases of which had p53 mutation in fecal specimens with the diagnostic sensitivity rate of 57.5%. Analysis of fecal p53 gene mutation had relatively higher diagnostic sensitivity rate than the detection of serum carcinoembryonic antigen and fecal occult blood (P < 0.05) for the diagnosis of CRC. 3 of 20 colorectal adenoma had p53 mutation both in tumor tissues and fecal specimens. 10 of 15 gastrocarcinoma had p53 mutation in tumor tissues but none in fecal specimens. CONCLUSIONS: Analysis of fecal p53 gene mutation has relatively higher diagnostic sensitivity rate for diagnosis of CRC and is expected to be a relatively sensitive, specific and effective method for early diagnosis of CRC, especially for CRC screening in large scale of the population.

Adult↗

PubMed2004

[Experimental study of the biocompatible and osteoinductive behavior of the hydroxyapatite/ultra-high molecular weight polyethtlene composite].

OBJECTIVE: To compare the biocompatibility and osteoinductive behavior of HA (hydroxyapatite) and HA/UHMWPE (ultra-high molecular weight polyethtlene) composite in orbital implantation. METHODS: Osteoectomy of the upper orbital rim was perform on 24 adult New Zealand rabbits. The animals were randomly divided into 4 groups with 6 of each. The HA, HA/UHMWPE composite or UHMWPE (10 mm x 10 mm x 3 mm in size) was implanted to the upper orbital defect of the animal in respective group. Animals were sacrificed at 1, 4, 8, 12 weeks. Histopathologic sections of the implants were evaluated and compared with light and transmission electron microscopy study. RESULTS: During the experimental period of 12 weeks, there was no implant extrusion or displacement. In the groups of HA and HA/UHMWPE composite, vascular ingrowth and fibroblasts were observed shortly and osteocytes were seen at 8 weeks. Calcium deposition of the implants showed a laminar fashion at 12 weeks. In the group of UHMWPE, fibrous membranes were seen around the implant at 1 week. Transmission electron microscopy study showed that in the HA and HA/UHMWPE groups, fibroblasts and vascular ingrowth could be seen, but osteocytes were not observed. CONCLUSION: HA/UHMWPE composite demonstrated biocompatibility and osteoinductive property. It would be a good substitute for bone, particularly for orbital bone.

Animals↗

PubMed2004

[TH gene mutation in Chinese patients with autosomal recessive dopa-responsive dystonia].

OBJECTIVE: To explore the mutation of tyrosine hydroxylase(TH) gene in Chinese patients with autosomal recessive(AR) dopa-responsive dystonia(DRD) and to lay a solid basis for gene diagnosis of AR-DRD in China. METHODS: Mutation analysis of TH gene was performed in 5 probands with AR-DRD and 2 sporadic patients with DRD by use of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) combining DNA direct sequencing. RESULTS: The PCR-SSCP analysis and DNA direct sequencing following PCR revealed no mutation in all the 14 exons of TH gene. CONCLUSION: The mutation rate of TH gene in Chinese patients with AR-DRD is low, hence suggesting the genetic heterogeneity and a new locus for AR-DRD.

Asian People↗

PubMed2003

Bromate induces loss of heterozygosity in the thymidine kinase gene of L5178Y/Tk(+/-)-3.7.2C mouse lymphoma cells.

Potassium bromate (KBrO(3)) induces DNA damage and tumors in mice and rats, but is a relatively weak mutagen in microbial assays and the in vitro mammalian Hprt assay. Concern that there may be a human health risk associated with bromate, a disinfectant by-product of ozonation, has accompanied the increasing use of ozonation as an alternative to chlorination for treatment of drinking water. In this study, we have evaluated the mutagenicity of KBrO(3) and sodium bromate (NaBrO(3)) in the Tk gene of mouse lymphoma cells. In contrast to the weak mutagenic activity seen in the previous studies, bromate induced a mutant frequency of over 100 x 10(-6) at 0.6mM with minimal cytotoxicity (70-80% survival) and over 1300 x 10(-6) at 3mM ( approximately 10% survival). The increase in the Tk mutant frequency was primarily due to the induction of small colony of Tk mutants. Loss of heterozygosity (LOH) analysis of 384 mutants from control and 2.7 mM KBrO(3)-treated cells showed that almost all (99%) bromate-induced mutants resulted from LOH, whereas in the control cultures 77% of the Tk mutants were LOH. Our results suggest that bromate is a potent mutagen in the Tk gene of mouse lymphoma cells, and the mechanism of action primarily involves LOH. The ability of the mouse lymphoma assay to detect a wider array of mutational events than the microbial or V79 Hprt assays may account for the potent mutagenic response.

Animals↗

PubMed2003

Transfection properties of stabilized plasmid-lipid particles containing cationic PEG lipids.

Recent work has shown that plasmid DNA can be efficiently encapsulated in well-defined "stabilized plasmid-lipid particles" (SPLP) that have potential as systemic gene therapy vehicles [Gene Ther. 6 (1999) 271]. In this work, we examine the influence of ligands that enhance cellular uptake on the transfection potency of SPLP. The ligand employed is a cationic poly(ethylene glycol) (PEG) lipid (CPL) consisting of a lipid anchor and a PEG(3400) spacer chain with four positive charges at the end of the PEG (CPL(4)). It is shown that up to 4 mol% CPL(4) can be inserted into preformed SPLP, resulting in up to 50-fold enhancements in uptake into baby hamster kidney (BHK) cells. The addition of Ca(2+) to SPLP-CPL(4) (CPL(4)-incorporated SPLP) results in up to 10(6)-fold enhancements in transgene expression, as compared to SPLP in the absence of either CPL(4) or Ca(2+). These transfection levels are comparable to those observed for plasmid DNA-cationic lipid complexes (lipoplexes) but without the cytotoxic effects noted for lipoplex systems. It is concluded that in the presence of Ca(2+) and appropriate ligands to stimulate uptake, SPLP are highly potent transfection agents.

Animals↗

PubMed2003

[The signal transduction pathway related to hepatocellular carcinoma apoptosis induced by survivin antisense oligonucleotide].

OBJECTIVE: The expression of survivin gene in hepatocellular carcinoma cell line SMMC-7721 was blocked by means of antisense oligonucleotide (ASODN) transfection. To investigate the signal transduction pathway of apoptosis induced by survivin ASODN. METHODS: survivin ASODN was transfected into SMMC-7721 cells mediated by DOTAP liposomal reagent. The expression of survivin protein and mRNA was detected by western-blot and in situ hybridization method, respectively. Flow cytometer and TUNEL method were used to detect apoptosis. The changes in the expression and activity of p38MAPK and caspase-3 were assessed by western-blot, immuno-precipitation, RT-PCR, and kinase activity assess to study the relationship between the changes of p38MAPK and caspase-3 activity. RESULTS: The expression of survivin protein and mRNA decreased 84.6% and 69.7% respectively while apoptosis increased from 0.70% to 31.15% after transfected with survivin ASODN. P38MAPK activity increased significantly followed by increasing of caspase-3 activity after survivin ASODN transfection. Both p38MAPK and caspase-3 activity were inhibited after treated with inhibitor of p38MAPK, SB202190. CONCLUSION: Transfection of survivin ASODN could induce hepatocellular carcinoma cells apoptosis effectively through activated p38MAPK-caspase-3 signal pathway sequentially.

Antigens, Neoplasm↗

PubMed2003

Alterations of tumor suppressor genes (Rb, p16, p27 and p53) and an increased FDG uptake in lung cancer.

OBJECTIVE: The FDG uptake in lung cancer is considered to reflect the degree of malignancy, while alterations of some tumor suppressor genes are considered to be related to the malignant biological behavior of tumors. The aim of this study is to examine the relationship between FDG-PET and alterations in the tumor suppression genes of lung cancer. METHODS: We examined 28 patients with primary lung cancer who underwent FDG-PET before surgery consisting of 17 patients with adenocarcinoma, 10 with squamous cell carcinoma and 1 with large cell carcinoma. The FDG-PET findings were evaluated based on the standardized uptake value (SUV). Alterations in the tumor suppressor genes, Rb, p16, p27 and p53, were evaluated immunohistochemically. RESULTS: The FDG uptake in lung cancer with alteration in each tumor suppressor gene tended to be higher than in those genes without alterations, although the differences were not significant. In 15 tumors with alterations in either tumor suppressor genes, the FDG uptake was 6.83 +/- 3.21. On the other hand, the mean FDG uptake was 1.95 in 2 tumors without alterations in any genes. The difference in the FDG uptake between the 2 groups was statistically significant (p < 0.001). CONCLUSIONS: In conclusion, the presence of abnormalities in the tumor suppressor genes, which results in an accelerated cell proliferation, is thus considered to increase the FDG uptake in lung cancer.

Adult↗

PubMed2003

Molecular characterization of artemin and ferritin from Artemia franciscana.

Embryos of the brine shrimp, Artemia franciscana, exhibit remarkable resistance to physiological stress, which is temporally correlated with the presence of two proteins, one a small heat shock/alpha-crystallin protein termed p26 and the other called artemin, of unknown function. Artemin was sequenced previously by Edman degradation, and its relationship to ferritin, an iron storage protein, established. The isolation from an Artemia expressed sequence tag library of artemin and ferritin cDNAs extends this work. Artemin cDNA was found to contain an ORF of 693 nucleotides, and its deduced amino-acid sequence, except for the initiator methionine, was identical with that determined previously. Ferritin cDNA is 725 bp in length with an ORF of 516 nucleotides. Artemin amino-acid residues 32-185 are most similar to ferritin, but artemin is enriched in cysteines. The abundance of cysteines and their intramolecular spatial distribution suggest that artemin protects embryos against oxidative damage and/or that its function is redox regulated. The conserved regions in artemin and ferritin monomers are structurally similar to one another and both proteins assemble into oligomers. However, modeling of the quaternary structure indicated that artemin multimers lack the central space used for metal storage that characterizes ferritin oligomers, implying different roles for this protein. Probing of Northern blots revealed two artemin transcripts, one of 3.5 kb and another of 2.2 kb. These transcripts decreased in parallel and had almost disappeared by 16 h of development. The ferritin transcript of 0.8 kb increased slightly during reinitiation of development, then declined, and was almost completely gone by 16 h. Clearly, the loss of artemin and ferritin during embryo development is due to transcriptional regulation and proteolytic degradation of the proteins.

Amino Acid Sequence↗

PubMed2003

Fos expression in serotonergic neurons in the rat brainstem following noxious stimuli: an immunohistochemical double-labelling study.

In order to detect whether there were different expression patterns of Fos protein induced by somatic or visceral noxious stimulation in the serotonergic neurons in the rat brainstem, an immunohistochemical double-labelling technique for serotonin (5-HT) and Fos was employed after subcutaneous or stomach injection of formalin. The two stimuli were matched in pilot experiments to produce maximum Fos expression. The expression of Fos protein in 5-HT-containing neurons (5-HT/Fos co-localized neurons) could be observed in the ventrolateral subdivision of the midbrain periaqueductal grey, interpeduncular nucleus, paramedian raphe nucleus, all of the brainstem raphe nuclei, the alpha part of the gigantocellular reticular nucleus and the lateral paragigantocellular reticular nucleus. The locations of the 5-HT/Fos co-localized neurons in the brainstem of animals subjected to somatic noxious stimulation were similar to those subjected to visceral noxious stimulation. However, the number and proportion of the 5-HT/Fos co-localized neurons in the median raphe nucleus and nucleus raphe obscurus of the rat subjected to visceral noxious stimulation were statistically greater than those in rats subjected to somatic noxious stimulation. These results suggest that serotonergic neurons in median raphe nucleus and nucleus raphe obscurus have a tendency to higher neuronal activity after visceral noxious stimulation.

Animals↗

PubMed2003

Nitrogen removal via nitrite at normal temperature in A/O process.

In order to study the nitrogen removal via nitrite at normal temperature in anoxic/oxic (A/O) process for treating domestic wastewater, the influence of pH, free ammonia (FA), dissolved oxygen (DO), and hydraulic retention time (HRT) were studied. Results indicated that it was possible to remove nitrogen via nitrite in A/O process, if the temperature was between 18 and 25 degrees C and pH was below 7.5. Even if FA was as low as 0.06 mg NH3-N/L, it would inhibit the nitrobacteria. However, FA could not be the sole factor. Whether denitrification went thoroughly or not could affect the nitrification pathway. If denitrification went well, nitrite accumulation could recover in a short while. Nitritification lagged nitratification, so that short HRT would help nitrite accumulation. On the other hand, extended aeration would reduce nitrite accumulation.

Nitrites↗

PubMed2003

[Advances of combined treatment for chronic hepatitis B with lamivudine].

This paper summarized the effects of the treatment of chronic hepatitis B (CHB) by lamivudine combined with traditional Chinese medicine or western medicine in the past few years. Combined treatment of lamivudine and the other medicine had higher efficiency than lamvudine alone in the treatment of CHB. The Combined treatment should be a tendency of the treatment for chronic hepatitis B. The focal point is that the traditional Chinese recipe produces a multitarget effect in the treatment of CHB. The combined treatment of lamivudine and traditional Chinese recipe can reduce the treatment course and the recurrence rate. Combined treatment of traditional Chinese medicine and western medicine has notable superiority and broad developing prospect in the treatment of CHB.

Drug Therapy, Combination↗

PubMed2003

[Effects of land utilization of sewage sludge on grass and soils].

Effects of land disposal of sewage sludge on grass and soil environment were studied. The sewage sludge used was from Northern Shenyang Wastewater Treatment Plant. The results showed that contents of nutrient in the soil were increased after sewage sludge application, especially for organic matter. Grass biomass were increased and the green period were extended with a better growth of the lawn. The heavy metal contents in the soil were increased with Cd contents beyond 2nd grade national environmental quality standard for soils. However, Pb, Cu, Zn contents not accumulated heavily. Poa annua had better ability of absorbing and accumulating Pb from the sewage sludge. When the application rate of sewage sludge capacity was at 25, 30, 60 t.hm-2, Zoysia japonica expressed significant absorption and accumulation of Cd, Cu, Zn.

Agriculture↗

PubMed2003

[Experimental study of using xenologous sclera as wrapping materials for hydroxy apatite(HA)].

OBJECTIVE: Use xenologous sclera (pig sclera) as wrapping materials for hydroxyapatite (HA) ocular implants in enucleated New Zealand white rabbits. METHODS: Ten rabbits were unilaterally enucleated and the sockets implanted with 10 mm HA spherical implants. All implants were wrapped with pig sclera. The rabbits were killed 4 weeks later and the sockets were examined clinically for inflammation and implant exposure. Exenterated specimens were assessed histopathologically for inflammation and vascularization. RESULTS: No clinical evidence of implant exposure or extrusion was detected in rabbits receiving pig sclera wrapped implants. Histopathologically the xenologous (pig) sclera displayed moderate inflammation, as well as maintain its lamellar arrangement without disruption. Fibrovascular ingrowth was complete in all implants. CONCLUSION: Xenologous (pig) sclera behaves similar clinically to homologous sclera as a wrapping material for spherical HA ocular implants in a rabbit model, and may represent a reasonable alternative to sclera in such procedures in humans.

Animals↗

PubMed2003

[Apoptosis in hepatoma cells induced by antisense oligodeoxynucleotide against survivin].

OBJECTIVES: To investigate the apoptosis induced by antisense oligodeoxynucleotide (ASODN) against survivin and the mechanisms after the hepatocellular carcinoma SMMC-7721 cells transfected with the ASODN. METHODS: The ASODN was transfected into SMMC-7721 cells mediated by liposomal reagent. The changes of cell cycle and apoptotic rate were detected by flow cytometry. The changes of cell skeleton was observed through confocal microscope. The activity of p38MAPK and caspase-3 were detected by immuno-precipitation and kinase activity assess methods, respectively. RESULTS: There were control, sense control, 400, 600, 800, and 1 000 ng/ml ASODN groups (I - VI). The apoptotic rats were 0.70%, 0.76%, 2.43%, 7.82%, 23.11%, and 31.35% in groups I - VI, respectively, which in the ASODN-transfected groups were higher than that in the control group (t or=20.9, P<0.01). The activity of p38MAPK increased significantly, when the ASODN was transfected at the concentration of 600 ng/ml or more, so did the caspase-3 activity (the p38MAPK and caspase-3 activity in groups I - VI were 7.03, 7.07, 13.47, 16.37, 43.97, 47.87 and 0.015+/-0.010, 0.014+/-0.002, 0.026+/-0.003, 0.042+/-0.001, 0.093+/-0.001, 0.100+/-0.001, respectively). CONCLUSIONS: ASODN targeting at survivin mRNA can induce G2/M stop, activate p38MAPK and caspase-3. The activated caspase-3 destroys the cell skeleton microfilament system, resulting in apoptosis.

Apoptosis↗

PubMed2003

[Study on recovery of ethyl acetate after extracting tripterygium wifordii extractum with ethyl acetate].

OBJECTIVE: To increase the recovery rate of ethyl acetate after extracting tripterygium wifordii extractum and to decrease product cost. METHOD: After extracting tripterygium wifordii extractum with ethyl acetate, 3 times saturated salt water was added in it so as to recovery ethyl acetate distilled under normal atmospheric pressure. Ethyl acetate containing salt water was purified through Na2SO4 column. RESULT: Ethyl acetate purified could be used repeatedly and the recovery rate was up to 85%. CONCLUSION: This method is completely adapted for mass production.

Acetates↗

PubMed2002

Lactate administration attenuates cognitive deficits following traumatic brain injury.

Moderately head injured patients often suffer long term neurological sequelae. There is no therapy for brain trauma and current treatments aim only to minimize secondary damage. These secondary effects are often triggered by the inability to re-establish ionic homeostasis after injury, due to large energy demands. Recent reports have demonstrated that neurons are capable of utilizing lactate as an energy source, thus this report examines the usefulness of lactate administration in the attenuation of behavioural deficits following a moderate brain injury. Lactate infusion (i.v.) was started 30 min after lateral fluid percussion injury and continued for 3 h. Cognitive deficits were determined using the Morris water maze. Lactate infused injured animals demonstrated significantly less cognitive deficits than saline infused injured animals. Thus, lactate infusion attenuated the cognitive deficits normally observed in this model, and therefore may provide moderately head injured patients with a treatment to help ameliorate the sequelae.

Animals↗