Biomedical subjects

J Fu

Publications and source records attributed to J Fu.

At least 109 records · Page 6Linked to original sources

PubMed2000

[Detection of Prader-Willi syndrome by methylation-specific PCR].

OBJECTIVE: Using a faster and more efficient method to diagnose Prader-Willi syndrome(PWS). METHODS: Differential DNA methylation at several sites in the PWS critical region where the maternal homologue is unmethylated and transcriptionally active. Methylation-specific PCR(MSPCR) is based on sodium bisulfite treatment of DNA, which converts unmethylated but not methylated cytosine residues to uracil, and PCR primers specific for the maternal and the paternal allele. Methylation analysis by Southern blot is made to validate the MSPCR result. RESULTS: Bisulfite-modified DNA from PWS patients amplified only with methylated allele-specific primer pair showed only maternal 174bp PCR product. MSPCR and PW71B methylation studies showed an abnormal pattern consistent with the clinical diagnosis of PWS. Untreated DNA does not produce a PCR product. CONCLUSION: MSPCR can be used to detect all presently testable causes of PWS (deletion, uniparental disomy, and imprinting mutation) in an efficient first step for stepwise diagnostic testing, compared with either Southern blot analysis which is more timeconsuming, or fluorescence in situ hybridization(FISH) which can not detect uniparental disomy or imprinting mutation.

Adolescent↗

PubMed2000

[IL-4 gene transfer induces the differentiation of cells and inhibits the activity of telomerase in hepatoblastoma cells].

OBJECTIVE: To investigate the effects of human interleukin-4(hIL-4) gene transfer on the differentiation and the activities of telomerase in hepatoblastoma cells. METHODS: Retroviral vector (PL-IL-4-SN) was employed to introduce hIL-4 gene into human hepatoblastoma cell line(Hep G2)cells. Trypan blue and Wright's stain, radioimmunoassay, in situ hybridization, flow cytometry, PCR-ELISA were used to determine the change in morphology and cell cycle, the expression of proto-oncogenes, the synthesis of AFP and the activities of telomerase in IL-4 gene transferred tumor cells. RESULTS: The shape of the hepatoblastoma cells tended to become relatively mature; the growth of the cells was significantly suppressed(P<0.05); the synthesis of AFP was reduced from 15.36+/-0. 67 ng x10(6) cells(-1); x24h(-1); to 3.26 +/- 1.43ng x10(6) cells(-1); x 24h(-1); the proliferation of the cells was significantly suppressed(P<0.05); the cell cycle was arrested at G(0)/ G(1) stage; the expression of c-fos, c-jun, c-myc and the activities of telomerase were remarkably decreased in IL-4 gene-modified Hep G2 cells. CONCLUSION: hIL-4 gene transfer could induce the differentiation of heptoblastoma cells and down-regulate the activity of tolemarase in Hep G2 cells.

Cell Differentiation↗

PubMed2000

[Development of a mouse cell line containing stably integrated copies of pMCLacI/Neo plasmid: a model for studying mutations in vitro].

OBJECTIVE: To establish a suitable model for studying the different mechanisms of mutation between expressed and non-expressed genes in mammalian cells. METHODS: The NIH3T3 cells were transfected with the linearized pMCLacI/Neo DNAs by liposome-mediated transfection, and grew in the presence of G418. One drug resistant cell clone was selected to proliferate and to be analyzed with Southern blot and RT-PCR analyses on its genomic DNAs. RESULTS: (1) Multiple copies of pMCLacI/Neo plasmid DNA were intactly integrated in the genomic DNAs of the cell clone. (2) One of lac I target genes in the integrated plasmid could be transcribed in the NIH3T3 cells while the other could not. (3) The pMCLacI/Neo plasmid DNA could be efficiently rescued from the genomic DNAs of the cell clone with the average rescue efficiency of 410 cfu/microg DNA. CONCLUSION: The NIH3T3 cell line containing copies of a stably integrated pMCLacI/Neo has been established. The two lacI target genes in the cell line could imitate the functional states of expressed and non-expressed genes in mammalian cells respectively. The cell line will be a useful model for studying the different mechanisms of mutation between expressed and non-expressed genes in mammalian cells.

3T3 Cells↗

PubMed2000

[Transmission and genetic effect of ting chromosome in cross progenies from octoploid Tritileymus with 4D nullisomic].

A pair of ting chromosomes (ti) added to 72180 4D nullisomic was subcentral centromere chromosome and was about 1/3-1/4 the size of a chromosome on the average length. It's chromosome configuration was 19.59" (18-20) + 0.46' (0-4) + 0.99" (0-1) + 0.96ti" (0-1) + 0.08ti' (0-2) at PMC MI. The cells with ring ti" account for 96.19%, of which 82.38% were free on each side of the equatorial plane. ti chromosome paired in advance, defered segregation and had no synapsis with a chromosome. When the cross progenies from 72180 4D nullisomic with octoploid Trilileymus were backcrossed to the 4D nullisomic used as the male, the transmitting rate of 2ti chromosome was six times higher than that where the nullisomic was used as the female. The transmitting and loss rates of ti chromosome were 50.38% and 18.34% respectively, and averagely each plant has 0.72 ti chromosome in the cross generations. The appearing rate of ti chromosome was 43.18% in root tip cell and 8.16% in PMC MI of the plants without ti chromosome. When the number of a chromosome was less than 42, the genetic effect of ti chromosome on the quantitative character was significant, while the number of a chromosome was 42, the genetic effect was not apparent.

Chromosomes↗

PubMed2000

[Regulatory effect of antisense VEGF121 cDNA transfection on angiogenesis and metastasis of human lung giant cell carcinoma].

OBJECTIVE: To study the regulatory effect of antisense VEGF121 cDNA transfection on endogenous VEGF secretion and angiogenesis of human metastatic lung carcinoma cell line PG and explore the significance of microvessel density (MVD) in tumor growth and metastasis. METHODS: The eukaryotic expression vectors bearing antisense VEGF121 cDNA was transfected into PG cells. Human umbilical vein endothelial cells (HUVEC) were cultured in conditioned mediums from transfected cells, and proliferation was determined by methyl thiazolyl tetrazolium (MTT) and 3H thymidine incorporation (3H TdR) assays in vitro. Microvessel density (MVD) in xenografted tumors in nude mice was analyzed by immunohistochemistry. RESULTS: The transfectant of antisense VEGF121 cDNA exhibited a reduction in VEGF secretion. HUVEC grown in conditioned medium from the antisense VEGF transfected cells exhibited a decrease in capacities of DNA syntheses and cell proliferation. MVD of tumor with transfected antisense VEGF gene was significantly lower than that in control vector. CONCLUSION: Antisense VEGF gene transfection can inhibit vascular endothelial cell proliferation in vitro and tumor angiogenesis in vivo, which may explain its inhibitory effects on tumor growth and metastasis.

Animals↗

PubMed2000

Expression of the human multidrug resistance gene mdr1 in leukemic cells and its application in studying P-glycoprotein antagonists.

OBJECTIVE: To investigate the retrovirus-mediated transfer and expression of multidrug resistance gene (mdr1) in hematopoietic cells and to develop a model for studying the possible reversal of the MDR-mediated phenotype. METHODS: A retroviral vector HaMDR expressing the human mdr1 gene was packaged by PA317 cells with a titer of up to 8.5 x 10(5) CFU/ml. K562 leukemia cells were infected with MDR retrovirus, and transfectant K562/MDR cells were generated. The integration and expression of the exogenous mdr1 gene in K562/MDR cells were determined by polymerase chain reaction and flow cytometry. The reversal ability of P-glycoprotein (P-gp) antagonists was analyzed by in vitro drug sensitivity, accumulation and efflux of rhodamine 123 (Rh123) in this model. RESULTS: Transduction with amphotropic MDR retrovirus resulted in integration and expression of the mdr1 gene in the resistant cells, where an aberrant splicing transcript of the mdr1 gene was found. The K562/MDR cells displayed a classic MDR phenotype with a 41-78 fold resistance to vincristine and colchicine in comparison with parental K562 cells. The drug sensitivity of K562/MDR cells to vincristine can be completely restored by cyclosporin A (CsA, 2 mg/L) and Cremophor EL (CRE 132 mg/L), either individually or in combination (P < 0.05). CsA (3 mg/L) can block the efflux pump function of P-gp shown by the significantly increased accumulation and efflux reduction of Rh123 in K562/MDR cells. CONCLUSIONS: Retroviral vector HaMDR allows transfection with high-level expression of the mdr1 gene in human myeloid progenitor cells K562. The transfected K562/MDR provides a simple, sensitive model for developing antagonists of P-gp and studying their mechanism of action.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2000

[The effect of splenectomy on circulating endotoxin clearance and tissue distribution of endotoxin in rats].

OBJECTIVE: To study the effect of splenectomy on circulating endotoxin clearance and tissue distribution of endotoxin, and investigate the potential mechanism(s) underlying inflammatory response and multiple organ damage following splenectomy. METHODS: 112 male Wistar rats were randomly divided into two groups: control group (n = 56, included omentectomy and mobilization of the spleen), and splenectomy group (n = 56). The latter was further sub divided into 10-min, 0.5-, 1.5-, 4-, 12-, 24-hour groups after endotoxin challenge. Tissue and systemic blood endotoxin concentrations were measured using the chromogenic limulus amebocyte lysate (LAL), which was modified by perchloric acid (PCA) pretreatment for samples. Liver function parameter and lung tissue myeloperoxidase (MPO) were also measured. RESULTS: After endotoxin administration, plasma endotoxin concentrations were higher in splenectomized rats than in controls at 10 minutes and 0.5 hour (P < 0.01). Endotoxin clearance was delayed in liver and lung in animals after splenectomy. MPO values of the control group were significantly higher than those of splenectomy groups (P < 0.01). CONCLUSION: Splenectomy can lead to impairment of intravascular clearance of endotoxin and endotoxin accumulation in liver and lung. Endotoxin accumulated in local sites may be involved in the development of inflammatory response and multiple organ dysfunction following splenectomy.

Animals↗

PubMed2000

[Analysis on the characteristic and trend of AIDS epidemics in Shandong].

OBJECTIVE: To analyse the data thru labs and field epidemiological investigation from 1987 to 1999, in order to find out the characteristics, sources of infections and its trend which would lead to the development of strategy, prevention and control of AIDS in Shandong. METHODS: Anti-HIV antibody was detected by ELISA and WB in the serum of high-risk groups. When Anti-HIV antibody was positive, personal and epidemiological history was investigated. The anticoagulated blood was repeatedly collected to verify the infected people. PBMCs were separated from the anticoagulated blood to collect previrus DNA. Gene sequence was then detected and subtype analysed by PCR using ABI company kit. RESULTS: Eight hundred five thousand eight hundred and one specimens were detected in the whole province from 1987 to 1999. 52 cases showed Anti-HIV antibody positive, with a rate of 0.06 per thousand. Of the 52 cases, 2 died. Sequence detection and subtype analysis of PBMC in 24 infected people showed that there were five HIV-1 subtypes M: A, B, B', C, E which were from 7 cities of the province. Blood and sexual transmission took the majority with proportions, 59.62% and 30.76% respectively. The subtypes from 13 blood donors were all B'. Among 10 labourers refurned from abroad and 1 spouse six cases were C, two were B, and another two were A and E subtypes respectively. Epidemiologic data showed that most of the infected people were mobile, making sexual transmission easy to occur. CONCLUSION: The moods of HIV/AIDS transmission in Shandong were mainly through blood and sexual contacts.

Acquired Immunodeficiency Syndrome↗

PubMed2000

[Inhibition of growth and metastasis of human giant cell carcinoma of the lung by transfection of antisense VEGF121 cDNA].

OBJECTIVE: To explore the effects of blocking the VEGF/VEGF receptor paracrine pathway on growth and metastasis of human lung carcinoma cell line PG and to evaluate its potential application in gene therapy of cancer. METHODS: The eukaryotic expression vectors bearing either sense-VEGF121 cDNA or antisense-VEGF121 cDNA was constructed and transfected into PG cells. In vitro and in vivo tests such as Northern blotting hybridization, Western blotting immunochemistry analysis, as well as xenografting in nude mice were used to analyze the effect of antisense-VEGF. RESULTS: The transfectants stably expressing antisense VEGF121 were observed to produce markedly reduced 3.3 kb VEGF mRNA and 45 KD, 41 KD, 32KD VEGF proteins. When xenografted s.c. into nude mice, growth and metastasis of the antisense-VEGF transfected cell lines were greatly inhibited when compared with control cells. CONCLUSION: Antisense VEGF gene significantly inhibited tumor growth and metastasis and may provide an experimental example for the development of antiangiogenic gene therapy.

Animals↗

PubMed2000

[Study on the differentiation and apoptosis of promyelocytic leukemia cells induced by tributyrin].

OBJECTIVE: To investigate the differentiation of NB4 and MR2 cells induced by tributyrin (TB) in combination with different doses of all-trans retinoic acid (ATRA) and to see if TB can induce apoptosis of NB4 and MR2 cells. METHODS: Cell differentiation was analyzed by NBT reduction and CD(11b), CD(14) and CD(33), apoptosis by morphology, DNA electrophoresis, flow cytometry (FCM) and TUNEL in situ hybridization, bcl-2 expression by reverse transcriptase polymerase chain reaction. RESULTS: 0.2 mmol/L TB in combination with different doses of ATRA could potentiate the differentiation of NB4 cells induced by ATRA alone. No MR2 cell could be markedly induced by ATRA alone or in combination with TB. Treated with 1 mmol/L TB for 24 hours NB4 and MR2 cells exhibited a morphological characteristic of apoptosis and typical DNA ladder on gel electrophoresis. FCM analysis showed that TB could interfere with cell cycle in NB4 and MR2 cells, with a similar ratio of sub-G(1) in both cell lines. TUNEL in situ hybridization confirmed these results. Further study showed that TB could gradually down-regulated bcl-2 expression. CONCLUSION: TB exerts synergetic effect on ATRA-induced differentiation and induces apoptosis in promyelocytic leukemic cells.

Apoptosis↗

PubMed2000

[The significance of the adhesion of CD(34)(+) stem/progenitor cells to fibronectin in the pathogenesis of chronic myelogenous leukemia].

OBJECTIVE: To investigate the significance of the adhesion of CD(34)(+) stem/progenitor cells to fibronectin in the pathogenesis of chronic myelogenous leukemia (CML). METHODS: (1) Integrin beta(1) chain (CD(29)) and alpha(4) chain (CD(49d)) expressions on CD(34)(+) cells were measured by flow cytometry in 30 untreated CML patients in chronic phase (CML-CP) and 10 healthy donors. (2) The adhesion function of immunomagnetic beads selected CD(34)(+) cells to fibronectin was detected by crystal violet staining in 5 untreated CML-CP patients and 5 healthy donors. (3) The effect of fibronectin on CFU-GM colony formation of bone marrow cells in 3 CML patients and 3 healthy donors was observed by limited dilution liquid microculture. RESULTS: (1) There was no significant difference in CD(29) and CD(49d) expressions on CD(34)(+) bone marrow cells between CML patients and healthy donors. (2) The adhesion of CD(34)(+) bone marrow cells to fibronectin decreased significantly in CML patients as compared with that in healthy donors (P < 0.01). (3) The CFU-GM colony formation was significantly inhibited by fibronectin in healthy donors (P < 0.01), but not in CML patients. CONCLUSION: The adhesion function abnormality of CML CD(34)(+) bone marrow cells to fibronectin may underlie the abnormal proliferation of CML progenitors.

Antigens, CD34↗

PubMed2000

Changes in the lifestyle of Mongolian pastoralists in China in connection with urbanization.

The objective of this study was to elucidate changes in the health-related lifestyle of Mongolian pastoralists in China in connection with their urbanization. A total of 592 people participated in a survey that included a medical examination and an interview questionnaire. Files of 72 pastoral Mongolians, 78 urban Mongolians, 380 urban Han/Man and 21 urban Hui were used for this analysis. Urban Mongolians consumed meat and milk products less frequently than did pastoral populations (p < 0.001), and consumed fish and vegetables more frequently than did pastoral populations (p < 0.001). Urban Mongolian consumed mutton, beef, rengyo fish, milk, milk tea, curd, butter, yogurt, and sheep milk less frequently (p < 0.05) and pork, sword fish, and dried milk more frequently (p < 0.05) than pastoral Mongolian. Male pastoral Mongolians were more likely to drink and smoke than were urban Mongolians (p < 0.01), urban Han/Man (p < 0.01), or urban Hui (p < 0.01). The lifestyles of pastoral Mongolians in Inner Mongolia, China have changed in connection with urbanization. Understanding of the traditional pastoral lifestyle and the urban-living acculturation process will contribute to maximizing the positive impacts of urbanization on people's health in Inner Mongolia.

Acculturation↗

PubMed2000

[Studies on biosorption of Pd2+ by bacteria].

The strain R08, showed relatively strong ability of adsorbing Pd2+, was screened from different source of bacterial strains. The strain R08 was identified as Bacillus licheniformis. The optimum pH value of Pd2+ biosorption by R08 dead biomass is 3.5. The biosorption is a rapid and non-temperature dependent process. The biomass and Pd2+ initial concentration in solution affected the biosorption process. The bosorptive capacity could reach 224.8 mg/g under the conditions of Pd2+ 200 mg/L, 0.4 g biomass/L, pH3.5 and 30 degrees C for 45 min. TEM observation showed that R08 biomass is able to adsorb and reduce Pd2+ ions to Pd0 particles. IR spectrum analysis indicated that -COO- and HPO(4)2- groups on the cell walls may involve in process of adsorbing Pd2+.

Adsorption↗

PubMed2000

[Studies on biosorption of Au3+ by Bacillus megaterium].

Some characteristics of Au3+ biosorption and bioreduction by Bacillus megaterium D01 biomass were reported. The optimum pH value of Au3+ biosorption by strain D01 was 3.0. The biosorption was a rapid process, reaching 95% of the maximal capacity within the first 5 min of contact. Temperature did not affect the biosorption. The biosorptive efficiency(99.1%) and capacity (302.0 mg Au3+/g dry weight biomass) were achieved under the conditions of pH 3.0 and 30 degrees C, both concentration with an initial Au3+/biomass radio of 305 mg/g dry weight for 30 min of the contact. The D01 biomass could reduce Au3+ in the solution to Au0, Au0 on the cells surface and in the contact solution could be crystallized to different forms gold crystals, Au3+ impregnated on SiO2 and alpha-Fe2O3 could be reduced to Au0 by D01 biomass. The results of electrochemical reaction indicated that the strain D01 exhibited a high selectivity for Au3+.

Adsorption↗

PubMed2000

[Dynamics of growth and total tanshinones accumulation in crown gall cultures of salvia miltiorrhiza].

AIM: To determine the dynamics of growth and total tanshinones accumulation in crown gall cultures of Salvia miltiorrhiza in MS and 67-V liquid media. METHODS: Fresh, dry weight and total tanshinones yields in the cultures and in the medium were determined every 5 days in crown gall suspension cultures. RESULTS: In MS medium, the logarithmic growth phase of crown gall cultures in S. miltiorrhiza was from the 5th to 30th days, and the stationary growth phase was from the 30th to 35th days. From the 25th to 30th days, physiological activity of crown gall cultures was higher and their growth was better. However, in 67-V medium, the logarithmic growth phase of crown gall cultures was from the 10th to 25th days, and the stationary growth phase was from the 25th to 35th days. Total tanshinones were largely accumulated in the cultures and in the medium after 25 days. The total tanshinones yield (60 mg.L-1) was reached at the 35th day. CONCLUSION: Knowing the regularity of the growth and total tanshinones accumulation in crown gall cultures of S. miltiorrhiza will be helpful to take proper regulative measures in order to obtain the maximum total tanshinones yield.

Abietanes↗

PubMed2000

[Affection of exogenous gibberellic acid (GA3) on endogenus hormones of Panax quinquefolium seed during its morphological after ripening period].

According to the determination of endogenus hormones variation of Panax quinquefolium seed during its morphological afterripenging period, and the affection of exo-GA3 on the endogenus hormones dynamics, it suggested that exo-GA3 couldn't be used for accelerate the growth of Panax quinquefolium embryo, but was helpful in relieving seed dormancy during physiological afterripening period.

Abscisic Acid↗

PubMed2000

[Biological effects of supplements on soil properties and the growth of Panax quinquefolium].

This paper suggests that the physical and chemical characteristics of soil in American ginseng field were greatly improved after utilization of supplement on soil. Compared with the contrast, the soil gravity ratio decreased from 0.812 g/cm3 to 0.715 g/cm3, while the soil porosity increased from 69.36% to 73.03%. These improvements are benefit for the growth of Panax quinquefolium. Biological observations show that the fresh weight of ginseng root enhanced 53.8%, and the content of total saponins in root enhanced 0.5%-1% (get to 8.28%).

Carbon↗

PubMed2000

[Investigation of connective tissue growth factor's gene cloning].

OBJECTIVE: The human connective tissue growth factor(CTGF), as the responsive product of immediate early gene, was cloned for the investigation of cellular primary gene responded and healing repairing. METHODS: RT-PCR was performed with the mRNA of HUVE cell stimulated, the three clones of CTGF, via mutational modified, were ligated to a complete gene that identified with sequencing. RESULTS: The sequencing indicated that this CTGF gene contains complete coding region and the 3'-noncoding region which is difference with the reported sequence. CONCLUSION: A new human CTGF gene was cloned.

Base Sequence↗