Biomedical subjects

Qi Dong

Publications and source records attributed to Qi Dong.

33 records · Page 2Linked to original sources

PubMed2005

[Effects of microencapsulated CHO cells modified with maspin gene on the motility and adhesiveness of breast carcinoma cells Bcap37].

OBJECTIVE: To investigate the effects of microencapsulated Chinese hamster ovary (CHO) cells modified with maspin gene on the motility and adhesiveness of breast carcinoma cells Bcap37 and to explore the possibility and feasibility of its clinical application in treatment of malignant tumors. METHODS: After the Bcap37 cells were co-cultured with the microencapsulated CHO cells modified with maspin gene, their motility and adhesion to vascular endothelial cells (ECV304), changes in CD44v6 and E-cadherin expression were examined. RESULTS: After the treatment, the motility of Bcap37 cells, their adhesion to vascular endothelial cells ECV304 and the CD44v6 expression were significantly reduced. The adhesiveness of Bcap37 cells and their E-cadherin expression were significantly enhanced. CONCLUSION: The microencapsulated CHO cells modified with maspin gene decrease motility and adhesiveness of breast carcinoma cells Bcap37, which help explain the anti-metastatic effects of maspin.

Animals↗

PubMed2005

[Development of ZM-1 tissue microarrayer].

ZM-1 tissue microarrayer designed by our group is manufactured in stainless steel and brass. It features an easier and faster preparation for tissue microarrays. By means of it, a group of biopsy needles are used to punch the donor tissue specimens respectively, and all the needles with the punched specimen cylinders are arranged into the array-board, where small holes have been digged to fit the needles. All the specimen cylinders arraying and the tissue microarray block's shaping are finished simultaneously. ZM-1 tissue microarrayer with a lower cost of manufacture, is capable of preparing the tissue microarrays conveniently, efficiently and quality-controllably.

Equipment Design↗

PubMed2004

Induction of HSF1 expression is associated with sporadic colorectal cancer.

AIM: To explore the activation of signal transduction pathways related with the carcinogenesis of sporadic colon cancers. METHODS: A gene array monitoring the activation of 8 signal transduction pathways (PathwayFinder GEArray) was used to screen the differentially expressed genes between colorectal cancer and normal colon tissues. The differentially expressed genes were further analyzed by RT-PCR, using RNA derived from colorectal cancer and normal colon tissue of 35 patients. RESULTS: The expression of HSF1, HSF27, HSP90 and iNOS was increased in colon cancer tissues compared to normal colon tissue using PathwayFinder GEArray. The RT-PCR results showed that the expression of HSF1 was increased in 86% (30/35) patients and the expression of iNOS was increased in 63% (22/35) patients. CONCLUSION: The induction of HSF1 gene expression is associated with sporadic colon cancer. HSF1 induces heat shock stress signaling pathway, which might play a role in the carcinogenesis of sporadic colorectal cancer.

Adult↗

PubMed2004

An fMRI study with semantic access in low proficiency second language learners.

Brain activity was measured with fMRI in twelve 10- to 12-year-old Chinese children who began learning English when they were 8 years old in order to find out whether there is a common or a distinct neural semantic system for native language (L1) and second language (L2) in low proficiency bilingual subjects. Although they performed less well in L2 in the semantic decision task administered during fMRI measurement, these subjects showed similar robust activation, for both languages, in brain areas involved in semantic processing (e.g. the left inferior frontal cortex). Within-subject and group analyses revealed no significant difference in the activation patterns for L1 and L2 in these regions. These results suggest that at least at single-word level, there are shared neural substrates for semantic processing of L1 and L2 even when one is at a very low L2 proficiency level.

Brain↗

PubMed2004

Mapping of verbal working memory in nonfluent Chinese-English bilinguals with functional MRI.

Existing cognitive and neural imaging studies have suggested a frontoparietal network of multiple, cooperative components for verbal working memory (WM). We used functional MRI to investigate whether this neural network is also involved in the processing of second language by nonfluent bilinguals. Twelve (five males, seven females) native Chinese speakers who had limited English proficiency were scanned while performing working memory tasks in Chinese and English. They were asked to make judgment continuously whether the word presented on the screen was semantically related to (i.e., the semantic tasks) another word presented two words earlier. On a different task (i.e., the phonological tasks), they were asked to make judgment whether the target word rhymed with the other word. A naming and judgment task in each language was adopted to control for the visual process, initial lexical process, and motor responses. Behavioral data showed that subjects performed better at tasks in their native language (Chinese, L1) than in English (L2). Imaging results showed that all working memory tasks in both L1 and L2 elicited a very similar pattern of left-hemisphere-dominated activation in the dorsolateral prefrontal cortex, pars opercularis region, pars triangularis region, precentral cortex, and parietal lobule. Consistent with the behavioral data, the volume of activation in the left opercularis region, left parietal lobule, and right precentral region was greater for L2 than for L1. These results suggest that working memory in L1 and L2 is mediated by a unitary neural system (i.e., frontoparietal region), which is capable of recruiting surrounding cortical resources to meet the increased computational demand caused by low L2 proficiency.

Adult↗

PubMed2004

Agreement in personality judgments within and between nonoverlapping social groups in collectivist cultures.

The social context hypothesis states that people behave differently in different social groups because group norms and context-specific interpersonal relationships uniquely affect behavior. Consequently, a person who is a member of different, nonoverlapping social groups (i. e., the members of different groups are unacquainted) should be judged consensually on personality traits within each group; however, between groups there should be less agreement in judgments. This research focused on cultural moderation of the social context effect in two collective cultures (China and Mexico) with different norms for interpersonal relationships. Among Chinese, there was greater consensus in trait judgments within groups than between groups, whereas in Mexico, agreement within and between groups was equivalent. Culturally based relationship norms that affect cross-context consistency of behavior and, in turn, the consistency of trait judgments across groups were described.

Adult↗

PubMed2004

[Induction of HSF1 expression and sporadic colorectal cancer].

OBJECTIVE: To explore the activation of the signal transduction pathways related with the carcinogenesis of sporadic colon cancers. METHODS: A gene microarray monitoring activation of 8 signal transduction pathways (PathwayFinder GEArray) was used to screen the differentially expressed genes between colorectal cancer and normal colon tissue. The differentially expressed genes were further analyzed by RT-PCR, using RNA extracted from cancer tissue and matched normal colon mucosa of 35 patients with colorectal cancer. RESULTS: The expression of hsf1, hsf27 and inos was increased in colon cancer compared with normal colon mucosa using PathwayFinder GEArray. The RT-PCR results showed that the expression of hsf1 was detected in 86% of patients(30/35)and the expression of inos detected in 63% patients(22/35). CONCLUSION: Hsf1 induces heat shock stress signaling pathway, which might play a role in the carcinogenesis of sporadic colorectal cancer.

Cell Cycle Proteins↗

PubMed2004

[Structural characterization of 5' flanking regulatory region of DNA repair gene Rad51].

OBJECTIVE: To clarify the regulatory elements of Rad51 gene in its 5'flanking region. METHODS: Various constructs were obtained by cloning different DNA fragments into pGL3 reporter vector. These constructs were then introduced into osteosarcoma cell line U2-OS by calcium phosphate method for transient expression of reporter gene, and luciferase activities were measured by luciferase assay. RESULTS: Cells transfected with pGL3 constructs containing fragment -964 to +1430 and -733 to +1430 showed high luciferase activities. Obvious elevation of luciferase activities was also observed in cells transfected with pGL3 constructs containing four shorter derivative fragments -964 to -412, -746 to -412, -651 to -412 and -536 to -412. The highest luciferase activities were measured in transfected cells with plasmids containing fragment -964 to -412, and the lowest were in transfected cells with plasmids containing fragment -536 to -412. Luciferase activities in transfected cells with plasmids containing fragment -651 to -412 were higher than that in transfected cells with plasmids containing fragment -746 to -412. CONCLUSION: It is believable that the basic transcription-promoting element (promoter) for Rad51 gene resides between -536 to -412, and two transcription-enhancing elements (enhancer) or binding sites of positive transcription factors reside between -651 to -536 and -964 to -746, whereas one transcription-inhibiting element (silencer) or binding site of negative transcription factor may reside between -746 to -651.

5' Flanking Region↗

PubMed2003

[The study of 5-Aza-2'-deoxycytidine on transcription regulation of p16/CDKN2 gene demethylation in RKO human colorectal cell line].

OBJECTIVE: To explore the transcription regulation of DNA 5'CpG island demethylation on p16/CDKN2 tumor suppressor gene and effects of growth on RKO human colorectal cancer cell line. METHODS: RKO cell line was exposed to the specific demethylating agent, 5-Aza-2'-deoxycytidine, for seventy-two hours to detect whether the silencing of p16/CDKN2 cell cycle regulatory gene could be reversed. Methylation-specific PCR (MSP), T-A cloning and sequence analysis were evaluated for methylation status. Growth speed, expression of DNA methyltransferase mRNA, p16/CDKN2 mRNA and protein were determined by MTT assay, reverse transcription polymerase chain reaction (RT-PCR), Real-time PCR, immunohistochemistry and western blot. RESULTS: (1) All cytosines in CpG dinucleotides in untreated RKO cells with 5-Aza-2'-deoxycytidine remain as C, while all cytosines in treated RKO cells have been converted to thymidine. (2) RKO cell line after treatment with three different concentration 5-Aza-2'-deoxycytidine grew slowly and double time increased to 1.49, 1.64, 1.87-times respectively. (3) The expression of RKO cell p16/CDNK2 gene mRNA treated with 5-Aza-2'-deoxycytidine increased to 4.89, 16.91, 19.97-times respectively, but the expression of DNA methyltransferase mRNA was inhibited. (4) Immunohistochemistry and western blot indicated that 5-Aza-2'-deoxycytidine could increase the p16/CDKN2 gene protein expression. CONCLUSION: DNA promoter hypermethylation is associated with p16/CDKN2 gene silence in RKO human colorectal cancer cell line. 5-Aza-2'-deoxycytidine may effectively cause demethylation and inhibit the growth of tumor cell by reactivating the gene transcription silenced by aberrant hypermethylation.

Antimetabolites, Antineoplastic↗

PubMed2003

Continuous release of interleukin 12 from microencapsulated engineered cells for colon cancer therapy.

AIM: To explore the anti-tumor immunity against CT26 colon tumor of the microencapsulated cells modified with murine interleukine-12 (mIL-12) gene. METHODS: Mouse fibroblasts (NIH3T3) were stably transfected to express mIL-12 using expression plasmids carrying mIL-12 gene (p35 and p40), and NIH3T3-mIL-12 cells were encapsulated in alginate microcapsules for long-term delivery of mIL-12. mIL-12 released from the microencapsulated NIH3T3-mIL-12 cells was confirmed using ELISA assay. Transplantation of the microencapsulated NIH3T3-mIL-12 cells was performed in the tumor-bearing mice with CT26 cells. The anti-tumor responses and the anti-tumor activities of the microencapsulated NIH3T3-mIL-12 cells were evaluated. RESULTS: Microencapsulated NIH3T3-mIL-12 cells could release mIL-12 continuously and stably for a long time. After the microencapsulated NIH3T3-mIL-12 cells were transplanted subcutaneously into the tumor-bearing mice for 21 d, the serum concentrations of mIL-12, mIL-2 and mIFN-gamma, the cytotoxicity of the CTL from the splenocytes and the NK activity in the treatment group were significantly higher than those in the controls. Moreover, mIL-12 released from the microencapsulated NIH3T3-mIL-12 cells resulted in a significant inhibition of tumor proliferation and a prolonged survival of tumor-bearing mice. CONCLUSION: The microencapsulated NIH3T3-mIL-12 cells have a significant therapeutic effect on the experimental colon tumor by activating anti-tumor immune responses in vivo. Microencapsulated and genetically engineered cells may be an extremely versatile tool for tumor gene therapy.

3T3 Cells↗

PubMed2003

Clinical significance of vascular endothelial growth factor expression and neovascularization in colorectal carcinoma.

AIM: To clarify the association of vascular endothelial growth factor (VEGF) and microvascular density (MVD) expression with the angiogenesis and prognosis of colorectal cancer. METHODS: A total of 97 cases of colorectal carcinomas were examined by immunohistochemical staining (SP method), using anti-VEGF and anti-factor CD34(+) monoclonal antibodies. RESULTS: VEGF positive staining was obtained in 68 out of 97 cases (70.1 %), and observed mainly in the cytoplasm of tumor cells, and also frequently in stromal cells. VEGF expression was more intense in poorly differentiated adenocarcinoma in comparison with others, but there was no significant correlation between VEGF expression and age, sex and stage. A significant correlation was found between the MVD and grades, and there was no significant relationship between the MVD and age, sex, and stage. The MVD in the VEGF positive group (68 cases) was higher than that in the negative group. Upon multivariate analysis, the significant variables were stage, tumor grade and MVD; VEGF expression was not an independent prognostic factor. CONCLUSION: The expression of VEGF has a significant correlation with MVD; MVD expression has prognostic value but VEGF has not in colon cancer.

Adult↗

PubMed2002

Consequences of divorce on the adjustment of children in China.

Explored the consequences of divorce on children in China. In contrast to Western countries, divorce in China is relatively rare, occurring in approximately 10% to 15% of the population. Children from divorced families (n = 174) and matched intact families (n = 174) were selected from a larger sample of 1,294 children between 8 and 14 years of age. Divorce was relatively low in this sample (13.45%) of participants, consistent with rates observed in epidemiological studies in China. Mothers of divorced children reported higher levels of education but lower levels of income than mothers in intact families. Children in divorced families reported higher levels of anxiety and depression, and their mothers and teachers rated them as possessing more behavior problems on the Achenbach (1991) Child Behavior Checklist scales. Regression analyses revealed that rejecting and inattentive parenting styles, along with family status (divorce or intact), high maternal depression, and sex (boys) predicted significant amounts of variance associated with these negative outcomes. Results are discussed in terms of familial and cultural issues associated with these findings.

Adolescent↗

PubMed2002

Reduction of the incidence and mortality of rectal cancer by polypectomy: a prospective cohort study in Haining County.

AIM: To reduce the incidence and mortality of rectal cancer and address the hypothesis that colorectal cancer often arise from precursor lesion(s), either adenomas or non-adenomatous polyps, by conducting a population-based mass screening for colorectal cancer in Haining County, Zhejiang, PRC. METHODS: From 1977 to 1980, physicians screened the population of Haining County using 15 cm rigid endoscopy. Of over 240000 participants, 4076 of them were diagnosed with precursor lesions, either adenomas or non-adenomatous polyps, which were then removed surgically. All individuals with precursor lesions were followed up and reexamined by endoscopy every two to five years up to 1998. RESULTS: After the initial screening, 953 metachronous adenomas and 417 non-adenomatous polyps were detected and removed from the members of this cohort. Further, 27 cases of colorectal cancer were detected and treated. Log-rank tests showed that the survival time among those cancer patients who under went mass screening increased significantly compared to that of other colorectal cancer patients (P<0.0001). According to the population-based cancer registry in Haining County, age-adjusted incidence and mortality of rectal cancer decreased by 41% and 29% from 1977-1981 to 1992-1996, respectively. Observed cumulative 20-year rectal cancer incidence was 31% lower than the expected in the screened group; the mortality due to rectal cancer was 18% lower than the expected in the screened group. CONCLUSION: Mass screening for rectal cancer and precursor lesions with protocoscopy in the general population and periodical following-up with routine endoscopy for high-risk patients may decrease both the incidence and mortality of rectal cancer.

Adenoma↗

PubMed2002

[Preliminary study on protecting effect of two kinds of Chinese medical herbs on changes of three physiology systems in suspended rats].

Objective. To observe the protecting effect of two kinds of Chinese medical herbs on changes of blood circulation, muscle and skeletal systems in tail suspended rats. Method. Changes of blood circulation, muscle and skeletal systems in tail suspended rats (n=15), Chinese medical herb group 1 (n=15) and Chinese medical herb group 2 (n=15) after 30 d tail suspension were compared with those in control group rats (n=15). Result. Two kinds of Chinese medical herbs have obvious effect on improving the condition of blood circulation, and have some effects on improving the muscle and skeletal systems in tail suspended rats. Conclusion. Chinese medical herbs have a good prospect of being used in space flight, and further studies are needed.

Animals↗

PubMedDate not supplied

Social network positions and smoking experimentation among Chinese adolescents.

OBJECTIVE: To explore the relationship between peer social network positions and smoking experimentation among Chinese adolescents. METHODS: Self-administered questionnaires were administered to 1040 adolescents in grades 6, 8, and 10. Paired-friendship linkages were used to assign participants into 3 mutually exclusive social network positions. RESULTS: Overall isolates were more likely to have experimented with cigarettes than were group members or liaisons. However, among male 10th graders, more group members or liaisons had smoked than isolates. CONCLUSIONS: Smoking experimentation differs by social position, particularly among older adolescents. The association of social position with smoking experimentation could not be explained completely by traditional peer-related variables.

Adolescent↗