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Biomedical subjects

Jing Li

Publications and source records attributed to Jing Li.

At least 397 records · Page 22Linked to original sources
PubMed2003

Impact of rheumatoid arthritis-associated HLA-DRbeta1 subtypes on protein kinase A signaling.

OBJECTIVE: To investigate the impact of rheumatoid arthritis (RA)-associated HLA-DRbeta1 * 0401, * 0402, * 0403, * 0404 and * 0101 subtypes on the protein kinase A (PKA) signaling pathway. METHODS: Adenylate cyclase (AC), cAMP and PKA activity in transfectants expressing RA-associated HLA-DRbeta1 subtypes and their mutants were detected. RESULTS: Compared to HLA-DRbeta1 * 0402 transfectants, the RA-associated HLA-DRbeta1 * 0401, * 0404 and * 0101 transfectants produced significantly lower levels of AC, cAMP and PKA. CONCLUSION: RA-associated HLA-DRbeta1 molecules are involved in the pathogenesis of RA through down-regulation of the PKA signaling pathway.

Adenylyl Cyclases↗
PubMed2003

[Inhibition of ER alpha-mannosidase expression causes reduction and shortening of microvilli on rat liver epithelial cell WB-F344].

OBJECTIVE: To study the effect of N-glycosylation on the modification of microvilli on the surface of rat liver epithelial cell WB-F344 and the growth of the cells in culture. METHODS: Recombinant adeno-associated virus (rAAV) expression vector pAGX (+) containing an antisense or a sense fragment of 6A8 cDNA encoding a human alpha-mannosidase was constructed. The recombinant vectors or the mock were transfected into WB-F344 cells by means of lipofectAmine. The transfected cells were selected in G418 medium and cloned by means of limiting dilution. Integration of the transfected DNA into host DNA was detected by neo PCR. Rat liver ER alpha-mannosidase activity in cell supernatant was measured by using P-nitrophenyl-alpha-D-mannopyranoside as a substrate. Microvilli on cell surface were observed upon a scan electron microscope. The growth curves of the cells in culture were drawn. RESULTS: The cell clones transfected with antisense 6A8 showed reduction of ER alpha-mannosidase activity with various degrees. Clone AS1 and AS2 cell showed a pronounced reduction of the enzymatic activity. In the study on AS1 cells, Con A binding to the cells was found to be enhanced, cell growth in culture became slow from day 5. The microvilli on the cells were reduced and blunted. CONCLUSIONS: Transfection with antisense 6A8 resulted in reduction and blunting of microvilli on the surface of growing WB-F344 cells, which might be related to N-glycosylation modification.

Animals↗
PubMed2003

[Resistance of multicellular spheroids to taxol in human ovarian cancer and its mechanism].

BACKGROUND & OBJECTIVE: Cytotoxic anticancer drugs are less effective in killing tumor cells grown as multicellular spheroids than monolayer cell cultures. The aim of this study was to investigate the molecular mechanism of chemoresistance. METHODS: Ovarian cancer A2780, CAOV3 multicellular spheroids were obtained from three-dimensional culture. Expression of P-glycoprotein (P-gp) was determined using Western blot analysis and flow cytometry (FCM). The subcellular distribution of P-gp was also determined using laser confocal microscope. Reverse transcription-polymerase chain reaction (RT-PCR) was employed to detect the mdr1 mRNA of both monolayer cells and multicellular spheroids. Cell cycle profiles and apoptosis were also analyzed using FACS. The resistance was detected with trypan blue exclusion testing. RESULTS: Compared with control cells, no expression of P-gp was detected in monolayer cells, but expression of P-gp in aggregate cells was significantly elevated(P< 0.05). The mdr1 mRNA positive nodes were confirmed by RT-PCR in the aggregate cells. The percentage of cells increased in G(0)-G(1) phase and decreased in S and G(2)-M phase significantly in spheroids cells. Spheroids cells showed higher cell viability than monolayer cells (P(A2780)=0.003, P(CAOV3)=0.015). More apoptotic cells were induced by Taxol in MCS cells than in monolayer cells. CONCLUSION: Ovarian cancer A2780, CAOV3 multicellular spheroids cultures induced cell resistance to Taxol. High expression of P-gp was induced in ovarian multicellular spheroids and the cells were arrested in G(0)-G(1) phase.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2003

[PTEN coding product: a marker for tumorigenesis and progression of endometrial carcinoma].

BACKGROUND & OBJECTIVE: A new candidate tumor suppressor gene, called phosphatase and tension homology deleted on chromosome ten (PTEN), was the first gene that was found to be phospholipase tumor suppressor gene. Loss of PTEN function by mutation or other mechanisms is closely related to tumorigenesis and progression of multiple carcinomas. This study was designed to investigate the expression of PTEN in carcinogenesis and development of endometrium carcinoma. METHODS: The expression of PTEN were detected by reverse transcription polymerase chain reaction (RT-PCR) for 24 cases with endometrial carcinoma, 10 cases with endometrial atypical hyperplasia, 10 cases with endometrial hyperplasia,and 10 cases with normal endometrium and by SP immunohistochemical methods for 73 cases with endometrial carcinoma, 25 cases with endometrial atypical hyperplasia, 71 cases with endometrial hyperplasia,and 31 cases with normal endometrium. The results were compared with clinical parameters (histological classification, differentiation, depth of myometrium invasion, and clinical stage). RESULTS: PTEN expression levels of both RNA and protein in patients with endometrial carcinoma and endometrial atypical hyperplasia were significantly lower than those in patients with endometrial hyperplasia and normal endometrium. mRNA relative values were 0.35+/-0.13, 0.46+/-0.11, 2.32+/-0.32, and 2.45+/-0.51, respectively. Loss of PTEN expression rates were 66.67% (38/57), 76.00% (19/25), 5.63% (4/71), and 0 (0/31), respectively. Loss of PTEN expression in patients with endometrial carcinoma was significantly related to histological classification (P< 0.0001) and differentiation (P=0.0349). It was not related to depth of myometrium invasion and clinical stage(P >0.05). CONCLUSION: Loss of PTEN expression is an early event in endometrial tumorigenesis. Detection of PTEN protein may be a diagnostic biomarker for the earliest endometrial precancers and adenocarcinoma.

Biomarkers, Tumor↗
PubMed2003

Changes of phosphorylation of cAMP response element binding protein in rat nucleus accumbens after chronic ethanol intake: naloxone reversal.

AIM: To study the changes in the expression and phosphorylation of cAMP response element binding protein (CREB) in the rat nucleus accumbens after chronic ethanol intake and its withdrawal. METHODS: Ethanol was given in drinking water at the concentration of 6 % (v/v), for one month. Changes in the levels of CREB and phospho-CREB (p-CREB) protein in the nucleus accumbens were measured by immunohistochemistry methods. RESULTS: Ethanol given to rats in drinking water decreased the level of p-CREB protein in the nucleus accumbens (-75 %) at the time of exposure to ethanol. The decrement of p-CREB protein in the nucleus accumbens remained at 24 h (-35 %) and 72 h (-28 %) of ethanol withdrawal, which recovered toward control level after 7 d of ethanol withdrawal. However, chronic ethanol, as well as ethanol withdrawal failed to produce any significant alteration in the level of CREB protein in the nucleus accumbens. Naloxone (alone) treatment of rats had no effect on the levels of CREB and p-CREB protein in the nucleus accumbens. However, when naloxone was administered concurrently with ethanol treatment, it antagonized the down-regulation of p-CREB protein in the nucleus accumbens (142 %) of rats exposed to ethanol. CONCLUSION: A long-term intake of ethanol solution down-regulates the phosphorylation of CREB in the nucleus accumbens, and those changes can be reversed by naloxone, which may be one kind of the molecular mechanisms associated with ethanol dependence.

Alcoholism↗
PubMed2003

[Significance of expression of T lymphoma invasion/metastasis gene in ovarian cancer cells].

OBJECTIVE: To study the role of T lymphoma invasion/metastasis gene 1 (Tiam1) and protein in ovarian tumor cells. METHODS: Expressions of Tiam1 mRNA, Rac1 mRNA, and Tiam1 protein in four ovarian tumor cells A2780, Caov3, Skov3, and SW626 were studied by using RT-PCR and Western blot, respectively. The cell migration ability was analyzed by in vitro invasion assay. RESULTS: Expressions of Tiam1 mRNA and protein, as well as Rac1 mRNA were detected in all four ovarian tumor cells. There was a strong direct correlation between the levels of Tiam1 and Rac1 mRNA expression and migration potentials of all four ovarian cancer cells in vitro experiments. The increased expressions of Tiam1 mRNA were coincident with those of Rac1 mRNA, with a parallel relationship (P = 0.003, r = 0.874). Levels of Rac1 mRNA expression were significantly correlated with the potentials of tumor cell migration (P = 0.042, r = 0.814). CONCLUSION: Tiam1-Rac1 signaling pathway plays a positive role in assessing tumor cell invasion and metastasis and provides a new target for gene therapy of ovarian cancer.

Cell Movement↗
PubMed2003

[Comparison of tolerance to sequential continuous positive airway pressure therapy between patients after classical and after modified uvulopalatopharyngoplasty].

OBJECTIVE: To investigate the effect of uvulopalatopharyngoplasty (UPPP) on postoperation continuous positive airway pressure (CPAP) treatment in patients with obstructive sleep apnea hypopnea syndrome (OSAHS). METHODS: 66 OSAHS patients underwent UPPP were recruited and all were followed up for more than 12 months. Among them 24 patients were treated with classical UPPP, 42 had modified UPPP treatment. The efficacy of surgery was compared between the two groups. The post-operation tolerance to CPAP pressure was tested during sleep CPAP titration in 24 classical UPPP patients and in 15 modified UPPP patients. RESULTS: The validity ratio is 58.3% and 61.9% 12 months after operation. There was no significant difference between classical UPPP and modified UPPP in regard to surgery efficacy, and most of them need further CPAP therapy. During CPAP treatment, compared with untreated OSAHS patients, the highest CPAP pressure classical UPPP group could tolerant decreased significantly, however, classical UPPP group did not. 16.7% of classical UPPP patients had severe mouth air leak before optimal CPAP pressure was titrated, but none of the 15 post modified UPPP failed to sequential CPAP therapy. CONCLUSION: The efficacy was similar between modified UPPP and classical UPPP treatment, post modified UPPP patients had better tolerance to sequential CPAP treatment. It may be better to treat OSAHS patients with modified UPPP instead of classical UPPP.

Adult↗
PubMed2003

[Respiratory control during sleep and the development of nocturnal hypoxia in patients with obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: It is assumed that the reduced ventilatory control during sleep may be related to the nocturnal hypoxia in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and daytime CO(2) retention. METHODS: Oxygen desaturation index (ODI(4)), sleep time spent when SaO(2) was below 90% (SIT(90)), the lowest SaO(2) (LSaO(2)) and the mean SaO(2) (MSaO(2)) during sleep were measured in 24 OSAHS patients with daytime PaCO(2) > or = 45 mm Hg and 39 with PaCO(2) < 45 mm Hg. Hypoxic (DeltaP(0.1)/DeltaSaO(2)) and hypercapnic (DeltaP(0.1)/DeltaPaCO(2)) responsiveness were measured in 11 eucapnic and 4 hypercapnic patients during wakefulness, NREM and REM sleep stages. RESULTS: Compared with the eucapnic patients, all the hypercapnic patients had more severe hypoxia during sleep (P < 0.05). Although both groups had similar chemical responsiveness during wakefulness, the hypercapnic patients had lower DeltaP(0.1)/DeltaSaO(2) and DeltaP(0.1)/DeltaPaCO(2) during both REM and NREM sleep (P < 0.05). CONCLUSION: The depressed chemical responsiveness during sleep plays an important role in the development of nocturnal hypoxia in OSAHS patients with daytime CO(2) retention.

Carbon Dioxide↗
PubMed2003

Seventy-two cases of antidiabetic-induced hepatopathy treated by huatan yigan decoction.

UNLABELLED: In order to observe the therapeutic effects of Huatan Yigan Decoction ([symbol: see text] Decoction for resolving phlegm and replenishing the liver) on antidiabetic-induced hepatopathy, 129 cases were divided into two groups, 72 cases in the treatment group were administrated with Huatan Yigan Decoction and 57 cases in the control group with the liver-protecting drugs. Their liver function, plasma prothrombin time (PT), blood urea nitrogen and symptoms of the patients before and after treatment were observed during the three therapeutic courses. RESULTS: The total effective rate and cured rate of the treatment group manifested an obvious difference in comparison with those of the control group (P < 0.05 or P < 0.01). Even though the liver function, blood urea nitrogen (BUN) and symptoms in both groups were improved markedly, these indicators in the treatment group were improved more markedly than those in control group (P < 0.01). No adverse effect was found during the treatment. CONCLUSION: Huatan Yigan Decoction shows a repair action on hepatic injury.

Adult↗
PubMed2003

[Construction of PTTGas antisense expression vector and its inhibitory effects on human ovarian carcinoma cell line SK-OV-3].

BACKGROUND & OBJECTIVE: Pituitary tumor transforming gene (PTTG) is a new proto-oncogene and shows multiple actions of promoting tumorigenesis and metastasis. Most researches mainly focus on the problems of PTTG expression in different tumor tissues and its relative regulatory mechanisms, but no research of exploring the possibility of antisense blocking of PTTG gene has been reported by now. In present study, the authors constructed eukaryotic expression vector expressing full-length anti-sense PTTG mRNA and observed its blocking effect on the potential invasion of human ovarian carcinoma cell line SK-OV-3. METHODS: PCR primers containing designed enzyme cut sites were used for cloning full-length PTTG gene fragment, and the resulting PCR product was inserted into the eukaryotic vector pcDNA3.1 in the antisense direction. The recombinant vector was then transfected into SK-OV-3 by lipofectamine. The positive cell clone was screened by G418,PTTG,and bFGF at protein level expression were detected by Western blot analysis. The changes of cell proliferation were analyzed by MTT method. The biological behavior change of transfection positive cells was observed by colony formation in soft agar assay. RESULTS: SK-OV-3 clones stably expressing full-length recombinant pcDNA3.1- PTTGas were obtained.The expression of PTTG and bFGF proteins in transfected cells were decreased by 61.5% and 52.3% respectively as compared with non-transfected ones. The cell proliferation was accelerated in transfected cells. The number of colony formation is reduced significantly in transfected cells (2.4+/-0.8) as compared with non-transfected and empty vector transfected cells (23.3+/-5.7 and 21.5+/-7.9, respectively, P< 0.01). CONCLUSION: The recombinant vector pcDNA3.1-PTTGas is a novel tool and brings us a new possibility of anti-sense gene therapy targeted at PTTG in human carcinoma.

Cell Line, Tumor↗
PubMed2003

[Cloning and expressing the E2 subunit of pyruvate dehydrogenase complex].

OBJECTIVES: To construct the expression vector of the pyruvate dehydrogenase complex E2 subunit gene (PDC-E2). METHODS: The PDC-E2 gene was amplified from human lymphocytes with RT-PCR, and was cloned into pExSecI vector to induce the PDC-E2 expression. The products were identified with western blot and ELISA. RESULTS: The expression vector pExSecI/PDC-E2 was successfully constructed. The products could be identified by the specific self-antibodies in the sera from the primary biliary cirrhosis patients. CONCLUSION: High efficient expression vector of PDC-E2 lays the foundation for serum assay of primary biliary cirrhosis patients with prokaryotic expressing PDC-E2.

Cloning, Molecular↗
PubMed2003

[Tissue culture and plant regeneration of Helianthemum songaricum Schrenk].

The cotyledonary segments of sterile seedlings of Helianthemum Songaricum Schrenk were cultured on different media containing different phytohormons. It was found that the calli could be induced efficiently on MS basal medium supplemented with 10.0 mg/L NAA and 0.2 mg/L 6-BA. When calli were transferred on MS medium with 2.0 mg/L 6-BA and 0.2 mg/L NAA, shoots were produced. The frequency of shoot differentiation reached about 85%. The regenerated shoots were rooted on 1/2MS medium added with 0.5 mg/L NAA. The rooting rate was about 76%. Regenerated plantlets were successfully transplanted in soil, with a success rate of 67%.

Cistaceae↗
PubMed2003

[Studies on use and residue levels of pesticides in fruit and vegetable in Tianjin Area and its control measures].

OBJECTIVE: To investigate pesticide abuse on fruits and vegetables in Tianjin Area, to detect pesticide residues in fruits and vegetables, to study the methods for reducing pesticide residues in fruits and vegetables. METHODS: (1) A questionnaire on the pesticide application during growing fruit and vegetable was administered to 185 farmers in Tianjin Area. (2) According to the information from the questionnaire survey, fruit and vegetable samples were collected in four seasons around the year and measured for organophosphorus pesticide residues by gas chromatography. (3) Fruit and vegetable samples contained pesticide residue were treated by scald, immersion in 0.15% and 0.30% detergent solution, immersion in pure water, peeling and cutting root and pesticide residues were measured before and after the treatment. RESULTS: The percentage of pesticide abuse in growing fruit and vegetable was 65.00% in Tianjin area, and 31.60% of the fruits and vegetable samples collected in summer were positive for high toxic organophosphorus pesticides. Significant decrease of pesticide residue in fruit and vegetable was found by scald, immersion in 0.15% and 0.30% detergent solution, as well as peeling and cutting root, and over 80.00% pesticide residue in the samples could be reduced by scald. CONCLUSIONS: It is necessary to strengthen pesticide abuse control and market surveillance and inspection, in order to reduce the harmful effects of pesticide residue in fruit and vegetables to human health.

Chromatography, Gas↗
PubMed2003

[Early detection of hearing impairment in high-risk infants of NICU].

OBJECTIVE: Hearing impairment or loss is a common disorder at birth. Many perinatal conditions may also cause hearing impairment. The present study aimed at investigating the incidence and morbidity of hearing impairment in critically ill neonates with high risk factors in neonatal intensive care unit (NICU). METHODS: Patients were evaluated using the auditory brain-stem response (ABR) to detect hearing impairment or loss in 248 neonates stabilized or before discharge from the NICU during the period from Dec. 1999 to Aug. 2001 in SCMC. In this article, high risk factors of hearing loss included severe asphyxia, hyperbilirubinemia and very low birth weight, persistent pulmonary hypertension or on a ventilator, exposed to ototoxic medications such as aminoglycosides and diuretics, a family history of hearing loss, meningitis and craniofacial anomalies, etc. Screening test was performed with a 70 dB (SPL) hearing level click stimulus to each ear. RESULTS: Seventy-two newborns had detectable hearing impairment in all the patients studied, the incidence of hearing impairment was 29.03%. Among them 3 cases had serious hearing loss. Twenty cases were among the 50 asphyxiated newborns (40.0%); 24 were from the 91 neonates with hyperbilirubinemia (26.37%); 15 were from the 44 premature infant group (34.09%), three of 4 premature cases with birth weight less than 1 500 g had hearing impairment. Six cases were among the 15 newborns who used mechanical ventilation (40.0%); 19 cases were among the 46 newborns who received ototoxic agents (41.30%). CONCLUSIONS: Critically ill neonates with some specific high risk factors had a significantly high incidence of hearing impairment. Early hearing screening is necessary for neonates who are discharged from NICU.

Evoked Potentials, Auditory, Brain Stem↗
PubMed2003

[Expression and biological activities of TRAIL fusion protein gene].

AIM: To obtain and express the full-length of TRAIL gene in prokaryocytes. METHODS: The full-length of TRAIL gene was amplified from peripheral blood cells(PBCs)by RT-PCR and then cloned into the expression vector pGEX-2T. The TRAIL-GST was expressed in E.coli. RESULTS: Sequence analysis indicated that the sequence of TRAIL gene was identical with that in the GenBank. The TRAIL-GST was expressed in E.coli. Expressed product could inhibit the proliferation of KB and Hela cells and finally lead to their apoptosis. CONCLUSION: The TRAIL-GST with biological activity has been expressed in the prokaryotic system.

Apoptosis↗
PubMed2003

[Changes of telomerase activity and hTERT mRNA expression in the process of apoptosis of HL-60 cells induced by arsenic sulfide].

AIM: To explore the effect of arsenic sulfide on telomerase activity of HL-60 cells. METHODS: Telomerase activity was determined by PCR-ELISA. The expression of hTERT-mRNA was analyzed by semi-quantitative RT-PCR. Flow cytometry was used to analyze the cell cycle,apoptosis and CD11b expression of HL-60 cells. RESULTS: Treament of HL-60 cells with 0.3-0.6 mg/L arsenic sulfide for 72 h did not induce apoptosis of the cells, while 1.5-3.0 mg/L did. Furthermore, 1.5-3.0 mg/L arsenic sulfide inhibited the telomerase activity and hTERT-mRNA expression in HL-60 cells. Proportion of the cells in G2/M phase was increased when being treated with arsenic sulfide. 3.0 mg/L arsenic sulfide upregulated CD11b expression in HL-60 cells from 1.0 % to 6.8%. CONCLUSION: Arsenic sulfide can inhibit telomerase activity. The increase of proportion of HL-60 cells in G2/M phase may be related to the reduction of telomerase activity. High dosage of arsenic sulfide can slightly induce differentiation of HL-60 cells.

Apoptosis↗