Biomedical subjects
Publications and source records attributed to Li Zhang.
This study aimed at investigating the characteristics of table and graph that people perceive and the data types which people consider the two displays are most appropriate for. Participants in this survey were 195 teachers and under-graduates from four universities in Beijing. The results showed people's different attitudes towards the two forms of display.
BACKGROUND: It has been suggested that aggressive periodontitis (AgP) has a genetic basis, but this theory has not been confirmed. The intent of this investigation was to study whether specific interleukin (IL)-1 genotypes and/or alleles could be used to predict susceptibility to generalized AgP (GAgP) in Chinese. METHODS: The GAgP group consisted of 122 patients, and the control group included 95 healthy subjects. Single nucleotide polymorphisms at IL-1A (+4845) and IL-1B (-511, +3954) were analyzed by standard polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The polymorphism of a variable number tandem repeat (VNTR) in intron 2 of IL-1RN was detected by PCR amplification and fragment size analysis. RESULTS: There was no significant association of IL-1 polymorphisms with GAgP in the unstratified subjects. However, when cases were stratified by gender, the frequencies of A2+ genotype and allele 2 at IL-1A +4845 were significantly increased in male patients compared to male controls (genotype: odds ratio [OR] 5.58, 95% confidence interval [CI]: 1.09 to 28.68, P = 0.039; allele: OR 4.97, 95% CI: 1.01 to 24.50, P = 0.049; adjusted for age and smoking status). The frequency of IL-1B -511 A1/A2 heterozygote was significantly increased in male GAgP group compared to male controls (adjusted OR 3.16, 95% CI: 1.01 to 9.89, P = 0.048). In females, no significant differences were found between patients and controls in corresponding analyses at all polymorphic loci. A possible combined effect of IL-1B -511 polymorphism and smoking on the elevated risk to GAgP was observed. The OR of GAgP for combined A2+ genotype and smoking was 12.45 (95% CI: 1.43 to 108.06, P = 0.022), and for combined allele 2 and smoking was 18.25 (95% CI: 2.32 to 143.86, P = 0.006). CONCLUSIONS: The polymorphisms of IL-1A +4845 and IL-1B -511 may play an important role in determining GAgP susceptibility in Chinese males. Furthermore, a possible combined effect of the polymorphism of IL-1B -511 and smoking on GAgP susceptibility was suggested.
The interaction of Methylene Blue (MB) with chondroitin-4-sulfate (CHS) has been investigated using spectroscopic techniques, including UV-Vis absorption, Rayleigh resonance scattering (RRS), and circular dichroism (CD). The addition of CHS caused a decrease in the absorbance of MB at 664 nm with a new absorption band appearing at 570 nm, enhanced RRS at 314 nm and 560 nm, and also resulted in an intense CD signal at 568 nm. The Scatchard model has been applied to calculating the binding constant and the number of binding sites. The calculated parameters are consistent with the experimental results. The factors affecting the interaction were investigated. Quantitative spectroscopic methods were developed for the first time. They are based on the fact that a decrease in the absorption at 664 nm and an enhancement of the RRS intensity at 314 nm are proportional to the concentration of CHS added in a certain range. Satisfactory results were obtained on the determination of synthetic samples.
OBJECTIVE: To investigate the effect of homocysteine (Hcy) on nuclear factor-kappaB (NF-kappaB) activity in cultured rat vascular smooth muscle cells (VSMCs). METHODS: Rat VSMCs were stimulated with 0.25 mmol/L Hcy. Cells were collected and nuclear protein was extracted at 30 min, 1 h and 2 h following stimulation. NF-kappaB activity was examined by electrophoretic mobility shift assay (EMSA). RESULT: Baseline NF-kappaB nuclear binding in VSMCs increased more than 1.76-fold at 30 min (P<0.01), 1.91-fold at 1h (P<0.01) and 1.84-fold at 2 h (P<0.01) following stimulation of Hcy. CONCLUSION: Hcy can enhance transient mobilization of N-kappaB in VSMCs, which suggests that some regulating effect of Hcy on VSMCs might be exerted through NF-kappaB activation pathway.
In order to investigate the clinical efficacy of non-myeloablative allogeneic stem cell transplantation (allo-NST) and related technology in patients with hematologic malignancies, twenty-six cases of hematological malignancies (10 AL, 14 CML, 2 MM patients) received NST following conditioning regimens with fludara + cyclophosphamide + ATG (14 cases) and busulfan or melphalan + cyclophosphamide + ATG (12 cases), G-CSF (600 micro g/d) or G-CSF (300 micro g/d) + GM-CSF (300 micro g/d) were used for mobilizing peripheral blood stem cell. A combination of cyclosporine A (CsA) and methotrexate (MTX) was administered for GVHD prophylaxis. Patients will be eligible for donor lymphocyte infusion (DLI) or donor stem cell infusion (DSI) given in graded increments according to the chimeric formation and clinical reaction. Generally the dose of the first infusion was 1 x 10(7)/kg at 4th week post-transplantation. The engraftment analysis included the detection of microsatellite short tandem repeats (STRs), Bcr/Abl fusion gene, Philadelphia chromosome, HLA-locus analysis, sex chromosome and ABO blood type or blood subtype. The results showed that 22 patients (84.62%) were engrafted, among which 18 patients were full donor chimerism (FDC) up to now. Acute GVHD occurred in 3/26 cases (11.54%). Chronic GVHD was diagnosed in 6 of 26 (23.07%) evaluable patients. The incidence of infection and hemorrhage was low and slight. It is concluded that allo-NST is a safe and effective therapeutic method for hematologic malignancies, but the related technology such as selection of indication, conditioning regimen and transplantation immunotherapy should be studied further.
OBJECTIVE: To analyze the clinical characteristics and treatment of hematogenous disseminated tuberculosis. METHODS: Twenty-seven cases of hematogenous disseminated tuberculosis diagnosed by autopsy from 1961 to 2000 were retrospectively analyzed. RESULTS: Among these patients the disease was acute in 22 cases (including 3 non-reactive) and chronic in 5. Twenty cases (74%) were misdiagnosed before death, most of which were due to concomitant with or misdiagnosed as connective tissue disease, hematological disease or tumor. 63% of the cases had long-term use of corticosteroids or repeated chemotherapy. Most cases showed atypical clinical manifestations and chest X-ray lesions. The positive rate of tuberculin skin test and sputum for smear were low. Autopsy showed that all cases had active lung tuberculosis and the major extra-pulmonary organs involved were liver, spleen and lymph nodes. CONCLUSION: Unaware of the risk for tuberculosis among immune compromised patients was the main reason for misdiagnosis and corticosteroid abuse was common. Physician should be alert to the occurrence of hematogenous disseminated tuberculosis, especially in immune compromised patients with long-term fever and systemic injury. Direct smear and cultural examination as well as newer diagnostic approaches with sputum and tissue may be useful for a rapid and correct diagnosis.
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Particulate wear debris within the bone-prosthesis microenvironment generated by normal wear and corrosion of orthopaedic implants is considered to be one of the main factors responsible for chronic aseptic inflammation and development of osteolysis in the long-term instability and failure of total joint arthroplasty. While the decrease in bone volume caused by wear debris-induced osteolysis could have been compensated by enough new bone matrix secreted by osteoblasts. Actually, the normal osteoblastic population depend on the regular differentiation and proliferation of their progenitor cells--bone marrow mesenchymal stem cells (MSCs). This study aims to investigate the potential mechanism for the rat MSCs cytotoxicity upon exposure to Titanium (Ti) particles. Rat mesenchymal stem cells (rMSCs) isolated from 3-month-old male Sprague-Dawley rats by Percoll intensity gradient method were cultured in DMEM medium (low glucose) supplemented with 10% fetal bovine serum, 100 U/ml penicillin, and 100 micrograms/ml streptomycin in a humidified incubator with 5% CO2 at 37 degrees C. In order to gain the homogenous cell population, rMSCs were passaged to 3-4th subpassage which were used in all the experiment groups. Then rMSCs were seeded in the 6 well culture plates and exposed to three different circle diameters (mean size, TD1: 0.9 micron, TD2: 2.7 microns, TD3: 6.9 microns) with three different concentrations (0.1 wt%, 0.05 wt%, 0.01 wt%, W/V) at different durations (8 h, 16 h, 24 h,), respectively. Unexposed rMSCs were used as control. In the given periods of Ti loading, fluid shear stress (FSS) was applied to each group cells. The expression of F-actin and DNA of the rMSCs at the indicated time were determined with laser confocal scanning microscopy and image analysis software. The results showed that there was up-regulation expression of F-actin in the rMSCs without Ti particles loading but in the presence of FSS. Ti particles loading can suppress the expression of F-action and DNA of rMSCs, but this down-regulation response varied with the three circle diameter, concentrations and durations of Ti particles. Among three kinds of diametrically different Ti particles, submicron Ti particles (0.9 micron) had the greatest suppressive response on rMSCs, together with some apoptosis bodies. Under the same diameter condition, the inhibition induced by Ti particles loading was in a manner dependent on the particles concentration and exposure duration. The reductive effects produced from 0.1 wt% Ti was the greatest and earliest among the responses from Ti particles at three different concentrations; and the lower the concentration, the weaker the repressive influence. Furthermore, with the elongation of exposure to Ti particles, the expression of F-actin and DNA decreased gradually, the lowest level was at 32 h. These findings demonstrated that Ti particles loading can attenuate rMSCs' viability in a manner dependent on the circle diameter, particles concentration, treatment period, suggesting that a reduction in the number of viable MSCs together with a compromise of the their differentiation into functional osteoblast may exacerbate aseptic loosening of total joint implant. Further investigation into particles-mediated suppression of MCSs viability may reveal novel mechanism of implant loosening and aid in development and application of osteolytic drug therapy and the optimization of design and selection of future orthopaedic biomaterials, thereby improving long-term compatibility and stability for arthroplasty patients.
OBJECTIVE: To evaluate the health-related quality of life (HRQOL) in chronic hepatitis C (CHC) female patients, and to identify factors associated with impairment in HRQOL. METHODS: We enrolled 41 women cases with hepatitis C for 10 to 15 years and 51 health women in Guan area of Hebei province, China. HRQOL was assessed by the SF-36 by an interview. RESULTS: CHC female patients had significantly lower SF-36 scors in all subscales when compared to those of the non-HCV infected female population. CONCLUSION: CHC female patients have a reduced HRQOL. CHC alone is associated with significant impairment in HRQOL.
BACKGROUND & OBJECTIVE: ZD1839, an anilinoquinazoline, is an orally active, selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, which has been approved for the treatment of advanced non-small cell lung cancer by FDA. Nasopharyngeal carcinoma is of epithelial origin with overexpression of epidermal growth factor receptor and it remains unclear whether ZD1839 is useful in the treatment of nasopharyngeal carcinoma. The present study was designed to evaluate the effect of ZD1839 on nasopharyngeal carcinoma cell lines. METHODS: The effect of ZD1839 on nasopharyngeal carcinoma cells (CNE1, CNE2, SUNE1) was determined by MTT assay. The effect of ZD1839 combined with cisplatin (DDP) or 5-fluouracil (5-FU) on nasopharyngeal carcinoma cell CNE2 was also evaluated. Burgi formula was adopted to analyze combination effect. The distribution of cell cycle and cell apoptosis rate were analyzed by flow cytometry. RESULTS: The proliferation of nasopharyngeal carcinoma cell lines CNE1, CNE2, and SUNE1 was inhibited by ZD1839, and the effect was dose-dependent. The value of IC50 for the effect of ZD1839 on nasopharyngeal carcinoma cell lines CNE1, CNE2, and SUNE1 was 3.9 micromol/L, 5.6 micromol/L, and 5.5 micromol/L, respectively. ZD1839 could enhance the effect of DDP and 5-FU on CNE2 cells. The Q values by Burgi formula were 1.19+/-0.02 and 1.12+/-0.10, respectively. When CNE2 cells were treated with ZD1839 at the concentration of 0, 1.95, 3.9, 7.8, 15.6, 31.25 micromol/L, the percentages of G(0)/G(1) phase were (46.8+/-1.7)%, (48.8+/-1.6)%, (51.3+/-1.3)%, (54.0+/-1.3)%, (61.5+/-2.2)%, and (71.2+/-1.4)%, respectively; the percentages of S phase were (37.5+/-1.3)%, (35.8+/-1.6)%, (31.8+/-2.1)%, (34.3+/-2.7)%, (27.2+/-2.9)%, and (27.6+/-2.4)%, respectively;the percentages of G(2)/M phase were (15.7+/-0.4)%, (15.3+/-0.1)%, (16.9+/-0.9)%, (11.7+/-1.4)%, (11.3+/-0.7)%, and (1.1+/-0.8)%, respectively. When CNE2 cells were treated with ZD1839 at the concentration of 0, 1.95, 3.9, 7.8, 15.6, 31.25, 62.5 micromol/L, the rates of CNE2 cell apoptosis were (1.6+/-0.3)%, (1.7+/-0.3)%, (2.3+/-0.4)%, (3.3+/-0.4)%, (3.9+/-0.8)%,(8.0+/-1.1)%,and(14.3+/-2.3)%, respectively. CONCLUSION: ZD1839 inhibits the proliferation of nasopharyngeal carcinoma cells and enhances the effect of cytotoxic drugs.ZD1839 induces CNE2 cell cycle arrest in the G1 phase and higher concentration of ZD1839 could induce apoptosis.
In order to compare the effects of GM-CSF + IL-4 with the effects of IL-3 + IL-4 on the differentiation and development of dendritic cells (DCs) from mouse bone marrow, we cultured bone marrow hematopoietic progenitor cell in vitro and examined whether DCs induced by IL-3 + IL-4 (IL-3 DCs) differed from the DCs induced by GM-CSF + IL-4 (GM-CSF DCs) in morphology, yields, phenotype and endocytic activity. Scanning electron microscope, laser scanning confocal microscope (LSCM) and flow cytometer (FCM) were used. The results showed that the DCs induced by IL-3 + IL-4 and the DCs induced by GM-CSF + IL-4 had similar morphology, and the DCs induced by IL-3 + IL-4 expressed high level of major histocompability complex (MHC) class II. Besides, IL-3 DCs had the characteristics of higher yields and better consistency. But CD80 and CD86 were expressed at low levels or absent on IL-3-treated DCs. The capability of uptaking antigen of IL-3 DCs was more powerful than that of GM-CSF DCs. IL-3 could substitute for GM-CSF in culturing DCs from mouse bone marrow cells and could obtain the tolerance DCs that lack costimulatory molecules.
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OBJECTIVES: To screen polymorphisms in the upstream region of S100A8 gene and to detect whether the polymorphisms were associated with aggressive periodontitis. METHODS: Thirty aggressive periodontitis patients and twenty-eight healthy controls were recruited for the study with informed consent. All subjects were of Chinese descent and systemically healthy. The regions about 800 bp upstream from the ATG start codon in exon 2 of the S100A8 gene of 10 patients and 8 controls were amplified by polymerase chain reaction (PCR) and analyzed by direct sequencing. A single nucleotide polymorphism (SNP) at 94 bp upstream from the ATG start codon was selected, and then the shorter regions (about 250 bp upstream from the ATG start codon) of the rest subjects were also amplified by PCR and analyzed by direct sequencing. The frequency of the SNP and the distribution of the genotype were detected and compared between the two groups. RESULTS: A nucleotide substitution (A-->G) at 94 bp upstream from the ATG start codon was demonstrated in Chinese, which was in a cis-acting element, named gamma interferon response element (gamma-IRE) in intron 1 of S100A8 gene. All of the subjects that carried the polymorphism were heterozygous. There was no statistically significant difference in the frequency of allele 2 (corresponding to the nucleotide G) between patients and controls (11.7% vs. 17.9%, chi2 = 0.887, P > 0.05). The prevalence of the heterozygous genotype was 23.2% and 35.7% (chi2 = 1.07, P > 0.05) in patients and controls, respectively. CONCLUSIONS: This is the first report that a nucleotide substitution of S100A8 gene was demonstrated in Chinese. The frequencies of allele 2 and heterozygous genotype were lower in patients, but there is no statistically significant difference between the aggressive periodontitis patients and healthy controls in this preliminary study.
OBJECTIVE: To study the incidence of cases with rash and fever illness (RFIs) after measles vaccine (MV) inoculation. METHODS: During 1999 to 2002, 150 RFIs cases reported by the special measles surveillance system in Shandong province, China, were investigated and analyzed epidemiologically. RESULTS: 7 674 690 ml MV were distributed during 1999 to 2002 and the annual average incidence of RFIs cases after MV inoculation was 0.20/10 000 ml (0.2 ml per dose). There was significant difference of incidences each year (chi(2) = 10.13, P < 0.05). All RFIs cases were sporadically distributed without epidemiological links. Clinical symptoms showed that 88.67% of the 150 RFIs cases having > 38.5 degrees C fever and 75.33% of all cases appeared typical rash after 4 to 11 days (the medium was 8 days) after MV inoculation. The order of rash onset among RFIs cases was consistent with that of regular measles cases caused by wild virus. 68.67% of the RFIs cases had first MV inoculation and 94.71% were 8 to 12 month-olds. IgM sera antibody test from RFIs cases were rubella negative and 45.65% positive for measles. CONCLUSION: RFIs due to allergic reaction or measles vaccine virus infection might occur after MV inoculation. There seemed to be a correlation between RFIs incidence and the doses of MV. Measles virus genotype analysis needs to be carried out to confirm if the onset of some RFIs cases is aetiologically associated to MV vaccine virus infection.
BACKGROUND & OBJECTIVE: The molecular predictor for cisplatin sensitivity in advanced non-small cell lung cancer (NSCLC) is still an open question at present. The purpose of this study was to evaluate the relationship of the cisplatin sensitivity/prognosis with the expression of excision repair cross complement-1 (ERCC-1), metallothionein (MT), and p53 in the paraffin-embedded tissue of advanced non-small cell lung cancer (NSCLC). METHODS: From January 1994 to December 2001, 51 pathologically confirmed advanced NSCLC patients were included. All patients received cisplatin contained regimen chemotherapy (Gemzar + DDP or NVB + DDP) as the first line treatment. At the same time, the tumor samples were collected and the expression of ERCC-1, MT, and p53 in the tumor samples were examined by immunohistochemical method. The response rates and survival data were analyzed according to the over-expression or not of these three parameters (negative group/over-expression group). The response rates were compared by Chi(2) test. Kaplan-Meier method and Cox proportional hazards model were used for survival analysis. RESULTS: In these 51 patients, the expression rates of ERCC-1, MT, and p53 were 42.8%, 57.5%, and 37.8%, respectively. The response rates in negative group/over-expression group of ERCC-1, MT, and p53 were 33.3%/16.7%, 35.3%/27.3%, and 21.4%/35.3%, respectively (1.99, 1.29, and 0.61 times, respectively, P >0.05). The response rate in both ERCC-1 and MT negative group was 37.5%. In both ERCC-1 and MT over-expression (co-expression) group, the response rate was 14.3%. The former was 2.6 times of the latter (P >0.05). The average survival time in negative group/over-expression groups were 621/523 days (for ERCC-1), 556/479 days (for MT), 599/416 days (for p53), respectively. ERCC-1, MT, or p53 over-expression group showed poorer prognosis than those of negative group by Kaplan-Meier analysis. But in multivariate analysis, only p53 over-expression was an independent poor prognostic factor of survival time (Cox regression, P=0.009). CONCLUSION: Whether over-expression of ERCC-1 and MT can be used as a molecular marker of cisplatin resistance in advanced NSCLC patients need further study. Over-expression of p53 predicates poor prognosis for patients with advanced NSCLC.
This study aimed to evaluate the rheological characteristic of W/O microemulsion. Using the Low Shear-30 Sinus Rheometer, we assessed the effects of water percentage in microemulsion on the apparent viscosity of microemulsion at different shear rates and temperature, and on the viscoelasticity of microemulsion. The results demonstrated that with the increase of water, the apparent viscosities at four different shear rates increased exponentially. The fitted curve between water percentage and the apparent viscosity (eta) at low shear rate was steeper than the others. We found that viscous component (eta') and elastic component (eta") also increased exponentially when water percentage was increasing. This communication addressed the relationship between water percentage and eta, and discussed the physical meaning of the elastic component. The results suggest that both the viscous component and the elastic component present qualitatively physical nature, but the viscous component is more accurate than the other.
Targeting molecular components that are critically involved in the maintenance of genome stability is a promising approach for overcoming intrinsic tumor cell resistance to DNA-damaging treatments. In mammalian cells, the Ku-dependent non-homologous end-joining repair pathway is the predominant process for the repair of double-strand breaks (DSBs) in DNA. Previously, RNA aptamers were selected to efficiently block DNA-binding activity of the Ku protein in vitro. In the present study, we have tested the efficacy of RNA aptamers against the Ku protein as molecular sensitizer of MCF-7 breast carcinoma cells to DNA-damage. Toward this end, we established MCF-7 cell sublines stably expressing SC4 aptamer RNAs under the control of the human 7SL small nuclear RNA gene promoter. Vector-transfected (MCF/7SL) cells and cells stably expressing SC4 aptamers (MCF/SC4) were exposed to the anticancer drug etoposide and cellular responses to DNA-damage were evaluated. We found that the presence of RNA aptamers against Ku protein enhanced etoposide-induced growth inhibition of MCF-7 breast cancer. The SC4 aptamer-mediated sensitization of MCF-7 cells to the anticancer drug is attributable to an increased susceptibility of these cells to apoptosis. The observed effects cannot be accounted for by the differential expression levels of Ku protein in control and SC4 aptamer-expressing cells, but are rather due to augmented DNA binding-capacity of Ku protein, as demonstrated in in vitro studies. Thus, RNA aptamers against Ku protein show potential to sensitize MCF-7 breast carcinoma cells to DNA-damaging agents.