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Biomedical subjects

Li Li

Publications and source records attributed to Li Li.

At least 307 records · Page 17Linked to original sources
PubMed2005

[Relationships among expressions of hTERT, MDR1, MRP mRNA, and C-myc protein in non-small cell lung cancer].

BACKGROUND & OBJECTIVE: The latest researches showed that myc protein could up-regulate the expression of human telomerase reverse transcriptase (hTERT), multidrug resistance gene 1(MDR1), multidrug resistance-related protein (MRP) in some kinds of tumors, and hTERT is correlated with efficiency of anti-tumor chemotherapy. This study was to investigate relations among expressions of hTERT, MDR1, MRP mRNA, and C-myc protein in non-small cell lung cancer (NSCLC). METHODS: Expressions of hTERT, MDR1, MRP mRNA in 113 cases of NSCLC tissues were detected by in situ hybridization, expression of C-myc protein was detected by SP immunohistochemistry, their correlations with clinicopathologic features of NSCLC were statistically analyzed. RESULTS: Positive rates of hTERT, MDR1, MRP mRNA, and C-myc protein in NSCLC tissues were 80.5%, 51.3%, 80.5% and 68.1%, respectively. Expressions of MDR1, MRP mRNA, and C-myc protein were significantly related to that of hTERT mRNA (P<0.05). Expression of C-myc protein did not correlate with expression of MDR1 or MRP mRNA. All 4 factors have no correlation with clinicopathologic features of NSCLC (P>0.05). CONCLUSION: Expression of hTERT mRNA may be related to those of MDR1, MRP mRNA, and C-myc in NSCLC. Overexpression of C-myc protein may be one of the molecular regulatory mechanisms of hTERT mRNA.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2005

Characterization of the mechanisms of electrochemotherapy in an in vitro model for human cervical cancer.

Electrochemical treatment is among the most effective therapies in the management of cervical malignancy. However, the mechanism of action of this treatment remains largely unknown. Therefore, the purpose of the current project was to establish a suitable eletrochemotherapy regimen for cervical cancer and to investigate the mechanism of the therapy in an in vitro model for human cervical carcinoma. HeLa cells were used as a model for cervical cancer in this study, and the effect of electrochemical treatment on these cells was examined in four different dosage groups (5 V + 5 C, 10 V + 5 C, 5 V + 10 C and 10 V + 10 C). Our results showed that the combinations of lower voltage and higher current (5 V/10 V + 10 C) had a greater anticancer effect in this model as compared to other groups. In addition, we compared the cytotoxic effect between electrochemical treatment and different pH condition treatments in this system, and found that the efficacy of electrochemical treatment in cell killing was better than that of acidic or basic medium treatment. Moreover, we demonstrated that the efficacy of electrochemical treatment was correlated with the degree of ionization and alteration in pH scale. The electrodes were basic on the cathode side which elevated the cations K+, Ca2+ and Mg2+, while the electrodes were acidic on the anode side which reduced the anion Cl-. We also assessed the effect of electrochemical treatment on cell cycle distribution in HeLa cells and showed that the percentage of cells in the G1 phase of the cell cycle was increased (G1 arrest), while the cell population in the S phase was decreased. Furthermore, we demonstrated that the levels of the cell cycle regulator cyclin D1 expression were dramatically reduced when 5 V/10 V + 10 C treatments were applied to these cells, as determined by RT-PCR analysis. By contrast, no significant changes in the levels of cyclin B1, CDK1 or CDK4 were detected. Based on these observations, we conclude that the combination of lower voltage and higher current may be a potentially effective eletrochemotherapy regimen for cervical cancer in the clinic, and that the antitumor effect of electrochemical treatment on cervical carcinoma cells is mediated partly via regulating ionization degree, pH state and cell cycle control.

Carcinoma↗
PubMed2005

[Studies on quality standard of Peucedanum praeruptorum].

OBJECTIVE: To establish a quality standard of Peucedanum praeruptorum for Chinese Pharmacopoeia (2005). METHOD: The presence of (+/-)-praeruptorin A were identified and assayed by TLC and HPLC, respectively. RESULT: Linearity of marker was obtained over the range of 0.17696-0.88480 microg (r=0.9999). The average recovery rate was 99.72% (RSD=0.40%). CONCLUSION: TLC is specific. The method of quantity is accurate, reappearance, simple, rapid, and suitable for the quality control of P. praeruptorum.

Apiaceae↗
PubMed2005

A novel observation: melatonin's interaction with malondiadehyde.

OBJECTIVES: A purpose of this study is to determine whether melatonin, a novel antioxidant, can interact with malondialdehyde in an in vitro condition. METHODS: The reaction kinetics and thermodynamics of this reaction have been performed and a new product has been identified using liquid chromatography onlining with mass spectrometry. RESULTS: A new product generated with an interaction of melatonin and malondialdehyde has been identified to be a three-ring structure with a molecular weight 286, which has the specific wavelength absorption with the maximum at 345 nm. The reaction was completed within a few minutes and the product was proportional to the concentrations of the reactants. Based on its molecular weight and the deduced structure of the new product, we speculate that this reaction occurs between one melatonin molecule and one malondialdehyde and to form a 3 ring conjugated adduct. CONCLUSION: This is the first report to show that melatonin directly interacts with malondialdehyde to form a new product. The findings suggest that melatonin may detoxify unsaturated carbonyls and protect against cellular damage induced by oxidative stress.

Chromatography, Liquid↗
PubMed2005

[Relationship between NF-kappa B binding activity and expression of PPAR gamma-mRNA in the livers of rats with fatty liver disease].

OBJECTIVE: To investigate the changes of NF-kappa B binding activity, the expression of PPARr and their correlation in the liver of rats with fatty liver disease (FLD) induced by different pathogenic factors and to investigate the molecular mechanism of the inflammation in FLD. METHODS: 40 Wistar rats were randomly divided into 4 groups of ten each: normal group, alcohol group, fat-rich diet group, alcohol adding fat-rich diet group. The rats were sacrificed at the end of the 16th week from the starting day of the experiment. Serum and liver specimens were collected. Histological specimens were stained with HE, SudanIV, and Masson and then studied microscopically. The ultrastructural changes were also checked under an electron microscope. NF-kappa B binding activity and the expression of PPARr mRNA were determined by electrophoretic mobility shift assay (EMSA) and RT-PCR respectively. The correlations between NF-kappa B binding activity and the expression of PPARr and the biochemical indexes were analyzed. RESULTS: Steatosis, inflammation, necrosis and fibrosis were present in livers of the rats of all the experimental groups, and were most severe in the alcohol adding fat-rich diet group. NF-kappa B binding activity was markedly increased in the livers of the alcohol group (142+/-16.32) and of the alcohol adding fat-rich diet group (238+/-19.14) in comparison to the livers of the normal (73+/-9.24, F = 6.36, 17.93) and those of the fat-rich diet group (84+/-10.38, F = 5.96, 16.20). Binding activity was higher in the alcohol adding fat-rich diet group than that in the simple alcohol group, but there was no difference between those of the fat-rich diet and normal groups. The level of PPARr mRNA was lower in the livers of the alcohol, fat-rich diet, alcohol adding fat-rich diet groups (0.2530+/-0.069, 0.3647+/-0.082, 0.1226+/-0.054) than that of the controls (0.8097+/-0.094) (F = 15.43, 7.24, 21.45). NF-kappa B binding activity was correlated positively with the level of serum TNF alpha (r = 0.527, 0.639) and the content of MDA in the liver homogenates (r = 0.723, 0.537), but negatively with the expression of PPARr in the livers of the alcohol and the alcohol adding fat-rich diet groups (r = -0.568, -0.891). CONCLUSION: The enhanced nuclear factors NF-kappa B binding activity and decreased expression of PPARr play a pivotal role in the inflammatory response of FLD induced by alcohol and fat-rich diet. It may provide a new idea for treating FLD effectively.

Animals↗
PubMed2005

Demonstration of differential gene expression between sensitive and resistant ovarian tumor cells by fluorescence differential display-PCR analysis.

Chemotherapy plays a major role in cancer management; however, acquired drug resistance remains a significant problem for ovarian cancer treatment. Chemoresistance is regulated by the coordinated expression of a set of genes. Thus, the identification of genes specifically modulated in the process provides an important step toward the discovery of underlying molecular mechanisms in drug resistance events. We recently developed five drug-resistant human ovarian carcinoma cell lines, including two cisplatin (cis) resistant cell lines, two carboplatin (car) resistant cell lines and one taxol (tax) resistant cell line. In this study, we investigated differential gene expression between these resistant cell lines and their parental cell lines by the fluorescence differential display-polymerase chain reaction (FDD-PCR) technique. We first screened and identified differentially expressed genes in the resistant ovarian cancer cell lines, and we then sequenced and analyzed these genes by bioinformatics software. A total of 33 fragments were displayed in the two resistant cell lines (S-cis and S-car) derived from the sensitive SKOV-3 cell line, and 36 fragments were displayed in the three resistant cell lines (A-cis, A-car and A-tax) derived from the sensitive A2780 cell line. After purification, cloning, sequencing, and homology analysis on the NCBI BLAST GenBank, 12 gene fragments were identified from the resistant S-cis and S-car cells, and 23 gene fragments were identified from the resistant A-cis, A-car and A-tax cells. Although a homolog search of the NIH GenBank revealed that most of the gene fragments were not significantly associated with the known drug resistance-related genes, our study conclusively demonstrates that FDD-PCR is a useful tool for analyzing the differential gene expression between resistant and sensitive tumor cells and for identifying novel chemoresistance-associated genes and potential biological markers or genetic markers of drug resistance.

Base Sequence↗
PubMed2005

Evaluation of 7SL RNA gene sequences for the identification of Leishmania spp.

We evaluated the use of 7SL RNA gene sequences for the identification of Leishmania spp. A fragment (approximately 137 basepairs) of the 7SL RNA gene from 13 reference strains and 18 clinical isolates of 11 different Leishmania species was amplified and sequenced using conserved primers. Reference strains from each Leishmania spp. complex showed unique sequences. The nucleotide sequences were compared pairwise and a range of 81.0-99.3% intercomplex similarity was observed. Clinical isolates of the same species had sequences identical to the corresponding reference strains; thus, the intraspecies similarity was 100%. A phylogenetic tree derived from the 7SL RNA gene partial sequences was constructed and is in agreement with accepted phylogenetic schemes.

Animals↗
PubMed2005

[NEMO Delta 4-10 deletion of NEMO gene in Chinese incontinentia pigmenti cases].

OBJECTIVE: Incontinentia pigmenti (IP) is a rare X-linked dominant disorder that affects ectodermal tissues. In IP, mutations in NEMO lead to the complete loss of NF-kB activation creating a susceptibility to cellular apoptosis in response to TNF-alpha. Recently, a second nonfunctional copy of the gene, Delta NEMO was identified, opposite in direction to NEMO. Almost 90% of IP whose gene mutation type had been recognized have a recurrent genomic deletion of exons 4-10 of the NEMO (IKK gamma) gene, called NEMO Delta 4-10, which is necessary to activate the NF-kB pathway. Therefore, PCR-based detection of the NEMO deletion is a diagnostic measurement for IP. This study sought to analyze the NEMO Delta 4-10 deletion in NEMO gene of Chinese IP cases. METHODS: Seven IP cases and part of their families totally 15 persons were enrolled in this study. The 7 IP cases were aged 41 days to 8 years. Among them 1 was male and 6 were female. Four cases had family history of IP, the other 3 were sporadic cases. Fifty healthy children without any congenital diseases were taken as normal control group. According to the gene characteristics of IP, by PCR measurement NEMO Delta 4-10 deletion in NEMO gene was tested with specific primers In2/JF3R, and NEMO Delta 4-10 deletion in pseudogene Delta NEMO was checked out by primers Rev-2/JF3R. RESULTS: Five out of the 7 tested cases (case 1, 2, 3, 4, and 6) showed NEMO Delta 4-10 deletion in NEMO gene. The mothers of case 1 and case 6, 1a and 6a, also suffered from this disease, and their results were just the same as their daughters. For pseudogene Delta NEMO only case 2 and case 4 were proved having NEMO Delta 4-10 deletion, while other cases and families had negative results. For normal control group, NEMO Delta 4-10 deletion was not found either in NEMO gene or in their pseudogene Delta NEMO. CONCLUSION: Incontinentia pigmenti in most cases were caused by NEMO Delta 4-10 deletion in NEMO gene.

Child↗
PubMed2005

[Preparation of a monoclonal antibodies against Plasmodium falciparum glutamate dehydrogenase and establishment of colloidal gold-immunochromatographic assay].

OBJECTIVE: To prepare a monoclonal antibodies (mAbs) against glutamate dehydrogenase (GDH) of Plasmodium falciparum (FCC1/HN strain) and establish colloidal gold-immunochromatographic assay (GICA) for diagnosis of Plasmodium falciparum malaria. METHODS: Recombinant GDH was used to immunize Balb/C mice and the mAbs against GDH were prepared using hybridoma technique followed by identification of IgG isotype and its affinity. Protein-G affinity chromatography was employed to purify the antibodies, which were labeled with colloidal gold for establishment of GICA for Plasmodium falciparum detection. RESULTS: Six mAbs were obtained and identified as IgG1(kappa) of IgG isotypes with affinity constants (Kaff) ranging from 1 x 10(-8) to 2.8 x 10(-10). GICA had a sensitivity of 86.66%; and specificity of 96.43%; for Plasmodium falciparum detection compared with routine microscopic examination. CONCLUSION: The established GICA is rapid and accurate for Plasmodium falciparum detection with such potential utility as for instant diagnosis of Plasmodium falciparum malaria.

Animals↗
PubMed2005

[A family history of congenital fibrosis of the extraocular muscle with autosomal dominant inheritance].

To discover novel disease genes, a family with congenital fibrosis of the extraocular muscle was studied by a follow-up investigation, eye examinations and histo-pathological examination. There were fifteen cases suffering from congenital general fibrosis syndrome in four generations. They have congenital blepharoptosis, head tilt, chin lift, primary gaze fixed in a hypo- and exotropic position. The diagnosis is confirmed with positive forced duction testing in the affected eye. Furthermore, fibrosis of the extraocular muscles and hyaline degeneration was confirmed by histo-pathological examination. Except for different levels of restriction of the eyeball movements, other eye symptoms in positive patients are substantially identical. The genetic analysis showed that this disease was caused by autosomal dominant inheritance. The pedigree may be precious resource candidate for discovering disease gene related with congenital fibrosis of the extraocular muscle.

Adult↗
PubMed2005

[Effects of fentanyl on cytokines and MDA during cardiopulmonary bypass in patients undergoing valve replacement].

OBJECTIVE: To investigate the effect of fentanyl on cytokines and MDA in valve replacement surgery during cardiopulmonary bypass ( CPB). METHODS: Thirty ASA II approximately III adult patients scheduled for cardial valve replacement were randomly divided into 3 groups: Group A (fentanyl 30 microg/ kg), Group B (fentanyl 60 microg/kg), and Group C (fentanyl 100 microg/kg). Anesthesia was induced with medazalam 0.1 mg/kg, fentanyl 10 microg/kg and vecuronium 0.1 mg/kg Administered intravenously. After tracheal intubation the patients were mechanically ventilated with pure oxygen. P(ET)CO2 was maintained between 35 approximately 45 mmHg. Anesthesia were maintained with fentanyl infusion combined with intermittent intravenous bolus of midazolam and vecuronium. MAP, CVP, HR, P(ET)CO2, SPO2, nasal and rectal temperature were monitored continuously. Remained dose of fentanyl was infused before the CPB. Blood Samples were taken before the operation (T1 ), before the CPB ( T2 ), 30 min after aortic declamping (T3 ) , 2 h after aortic declamping (T4 ), and 24 h (T5 ) after the operation for determination of plasma levels of tumor necrosis factor (TNF-alpha), interteukin IL-6 and IL-10, MDA. RESULTS: There was no significant change in the age, body weight, aortic cross-clomp time, CPB time, and operation time. Levels of TNF-alpha, IL-6, IL-10 and MDA after the CPB in the 3 groups were significantly higher compared with T, (P <0.01 ), TNF-alpha, IL-6 and MDA levels at T3, T4 were significantly lower in Group B and C than those in Group A. IL-10 levels at T4, T5 were significantly higher in Group B and C than those in Group A, but levels of TNF-alpha, IL-6, IL-10 and MDA in Group B were not significantly different compared with those in Group C. The duration of stay in the ICU and time of endotracheal extubation were significantly longer in patients of Group C than those of Group A and B. CONCLUSION: CPB leads to a proinflammatory and antiinflammatory response, as well as oxygen free radicals release. Larger dose fentanyl seemed to be effective in reducing CPB-induced inflammatory response and ischemic reperfusion injury, but the effect was not dependent on dose while fentanyl dose reaching some value, at the same time the duration of stay in ICU and time of endotracheal extubation is longer.

Anesthetics, Intravenous↗
PubMed2005

[Correlation of expression of connexin to growth and progression of cervical carcinoma in situ].

BACKGROUND & OBJECTIVE: Gap junction intercellular communication (GJIC), mediated by connexin (CX), is the unique type of intercellular communication in carcinoma in situ (CIS). Changes in expression of CXs and function of GJIC may play roles in carcinogenesis of cervical cancer and progression of CIS. This study was to investigate the expression of CXs in normal epithelium (NE), hyperplasia, CIS, and invasive carcinoma (IC) of cervix, to explore correlation of expression of CXs to pathogenesis and progression of cervical CIS. METHODS: Expression of CX43 (mRNA, protein), CX26 (mRNA), and Ki-67 (protein) in 30 specimens of cervical NE, 22 specimens of cervical hyperplasia, 30 specimens of cervical CIS, and 26 specimens of cervical IC were detected by immunohistochemistry and in situ hybridization. RESULTS: In cervical NE, hyperplasia, CIS, and IC, positive rates of CX43 protein were 83%, 55%, 50%, and 30%, respectively, and positive rates of CX43 mRNA were 97%, 64%, 58%, and 46%, respectively; positive rates of CX26 mRNA was 93%, 68%, 55%, and 42%, respectively. Positive rates of CX43 (mRNA, protein) and CX26 (mRNA) were gradually decreased. Positive rate of CX was significantly lower in CIS group than in NE group (P < 0.05). The expressions of CX26 and CX43 were weaker in CIS group than in NE groupu their expressions were obviously decreased, or even vanished in the area of CIS adjacent to NE. Proliferating index (PI), indicated by expression of Ki-67 protein, was increased gradually in NE (5%), hyperplasia (12%), CIS (30%), and IC (62%)u the differences were significant (P < 0.05) between CIS group and other groups. CONCLUSIONS: CX26 and CX43 may play important roles in carcinogenesis of cervical cancer. CXs may inhibit tumorigenesis and cell proliferation; it might be key factors in earlier stages when cellular malignant phenotypes have been established, or NE has been transformed into CIS.

Carcinoma in Situ↗
PubMed2005

[The effect of down regulating of p27 on the activity of hematopoietic progenitor cells derived from umbilical cord blood and bone marrow ex vivo].

OBJECTIVE: To compare p27 interfering effect on the proliferation and hematopoietic potential of hematopoietic progenitor cells (HPC) derived from human bone marrow (BM) and umbilical cord blood (UCB), and investigate the related mechanism. METHODS: CD34(+) cells sorted from human BM by flow cytometry and isolated from UCB by a magnetic isolation system were infected with retrovirus-p27 antisense cDNA (p27AS) and cultured with cocktail-cytokines. The cell proliferation capacities were detected by cell growth curve and DNA content analysis, and the hematopoietic potential by colony formation assay. The protein expression of p27 and CDK2 were measured with Western blot. CD34(+) cells infected with retrovirus-p27 sense cDNA (p27SE) and virus-green fluorescence protein (GFP) were used as the control. RESULTS: Comparing with groups of GFP and p27SE, p27AS showed to accelerate the expansion of UCB HPC significantly (P < 0.01), the cell number of p27AS, p27SE and GFP increased by 197.3 +/- 47.7-, 12.7 +/- 8.1- and 41.8 +/- 30.6- fold respectively by the end of the 9-day culture, the BM HPC increased by 36.0 +/- 22.3-, 8.7 +/- 6.8- and 14.1 +/- 10.4-fold respectively in the same time as UCB HPC. Cell cycle analysis showed p27AS mainly promoted S phase of BM and UCB HPC. S phase cell percentages of UCB HPC infected with p27AS, p27SE and GFP were (17.0 +/- 4.8)%, (2.0 +/- 0.8)% and (4.1 +/- 1.8)% and that of BM HPC were (8.4 +/- 4.4)%, (1.0 +/- 0.7)% and (3.8 +/- 1.4)% respectively. The yields of colony formation of p27AS for BM and UCB was higher than that for GFP (P < 0.05). Western blot demonstrated the expression of p27 reduced in the p27AS group, while CDK2 increased in the group. The virus infection rate, cell growth rate and colony forming yields of BM HPC was inferior to that of UCB HPC. CONCLUSIONS: p27 gene interfering could promote HPC proliferation, hematopoietic potential and the response to stimulations of UCB HPC is higher than that of BM HPC ex vivo. It seems that cell cycle controlled by p27 was related to CDK2.

Antigens, CD34↗
PubMed2005

[Combination of external beam radiotherapy and 252Cf neutron intracavitary brachytherapy for cervical cancer].

OBJECTIVE: To evaluate the curative effect of 252Cf brachytherapy on advanced cervical cancers. METHODS: A total of 77 cervical cancer patients were staged into IIa-IVa according to the standard of International Federation of Gynecology and Obstetrics (FIGO), including 13 cases of stage IIa, 32 of stage IIb, 18 of stage IIIa, 10 of stage IIIb, and 4 of stage IVa. 252Cf brachytherapy was delivered at 8-11 Gy/fraction per week, the total dose of reference point A was 36-45 Gy in 4-5 fractions. The whole pelvic cavity was irradiated with 6 MV X-ray, 200 cGy/fraction, 4 times per week. The total dose of external beam radiotherapy was 45-50 Gy (the center of whole pelvic field was blocked by 4 cm in width after 20-36 Gy), the total treatment course was 5-6 weeks. The 3-year survival rate and late complication rate in bladder and rectum were evaluated. RESULTS: The local control rate of all patients after 3-year was 94% (72/77); the overall survival rate was 82% (63/77). In particular, the 3-year survival rate was 85% (11/13) for stage IIa, 94% (30/32) for stage IIb, 78% (14/18) for stage IIIa, 70% (7/10) for stage IIIb, 25% for stage IVa cancers. The late complication rate was 3% for cystitis, 5% for proctitis. CONCLUSIONS: Combination of 252Cf brachytherapy and external beam radiotherapy can be well-tolerated by cervical cancer patients. The 3-year survival rate for stage II and III patients is high and late complication rate in bladder and rectum is low.

Adult↗
PubMed2005

[SNP genotyping by multiplex amplification and microarrays assay and forensic application].

OBJECTIVE: Research on the application feasibility of SNP genotyping for forensic identification by microarrays. METHODS: Oligonucleotide microarrays which could detect 31 different SNPs were used. Population studies on 31 SNP loci was carried out in a sample of 109 unrelated Chinese Han individuals using oligonucleotide microarrays for genotype detection. The method was also applied to cases. RESULTS: No deviations from Hardy-Weinberg equilibrium could be found at the 31 SNP loci 4 loci were medium informative and 27 were high informative. The combination discrimination power (CDP) of the 31 optimal informative SNPs was 0.9999999999979. The matching probability was 2.13 x 10(-12). The average exclusion probability in duos and trios were 0.9609 and 0.9970 respectively. CONCLUSION: The data and case application demonstrated that SNP typing by oligonucleotide probe microarrays was a useful technique for paternity testing and individual identification.

Asian People↗
PubMed2005

[Discovery of biomarkers in the serum from patients with hypertensive disorder complicating pregnancy].

OBJECTIVE: To distinguish patients with hypertensive disorder complicating pregnancy from healthy pregnant women by examining serum protein fingerprinting. METHODS: Eight patients with hypertensive disorder complicating pregnancy and eight healthy pregnant women were tested by surface-enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS). RESULTS: At the molecular mass/charge (M/Z) value range from 1300-14,000, the content of three proteins with different M/Z values was obviously different. In spectrometry of patients with hypertensive disorder complicating pregnancy, proteins with M/Z 1325, 13,749 were significantly higher than that in healthy pregnant women (P < 0.05), that with M/Z 3245 was significantly lower than in healthy pregnant women (P < 0.05). CONCLUSIONS: There is difference in serum protein fingerprinting between healthy pregnant women and patients with hypertensive disorder complicating pregnancy.

Adult↗