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Hong Liu

Publications and source records attributed to Hong Liu.

At least 271 records · Page 15Linked to original sources

Genome-wide prediction and analysis of function-specific transcription factor binding sites.

DNA-binding transcription factors play a central role in transcription regulation, and the annotation of transcription-factor binding sites in upstream regions of human genes is essential for building a genome-wide regulatory network. We describe methodology to accurately predict the transcription-factor binding sites in the proximal-promoter region of function-specific genes. In order to increase the accuracy of transcription factor binding-site prediction, we rely on recent genome sequence data, known transcription factor binding-site matrices, and Gene Ontology biological-function-based gene classification. Using TRANSFAC position-frequency matrices, we detected individual and cooperating transcription-factor binding sites in proximal promoters of ENSEMBL annotated human genes. We used the over representation of detected binding sites in the proximal promoters as compared to the second exons to control specificity. We confirmed the majority of transcription-factor binding sites predicted in proximal promoters of immune-response genes with evidence from existing literature. We validated the predicted cooperation between transcription factors NF-kappa B and IRF in the regulation of gene expression with microarray transcript profiling data and literature-derived protein-protein interaction network. We also identified over-represented individual and pairs of transcription-factor binding sites in the proximal promoters of each Gene Ontology biological-process gene group. Our tools and analysis provide a new resource for deciphering transcription regulation in different biological paradigms.

Computational Biology↗

Prediction of IFN-gamma regulated gene transcription.

IFN-gamma, a cytokine promoting cell-mediated immunity and antiviral effects, regulates the expression of a large set of genes involved in the immune response. Based on logistic regression, an in silico model for predicting IFN-gamma regulated transcription has been developed by scoring the transcription factor binding sites on the putative promoters of regulated versus not regulated genes derived from the microarray data of IFN-gamma treated human macrophages. The model effectively discriminates the transcription factor binding sites that confer responsiveness to IFN-gamma from those that do not. The model has 65% true positive and 22% false positive rates when evaluated on a small validation set. In order to identify potential IFN-gamma regulated genes in the whole genome, the model has been used to screen 13,668 promoter pairs of human-mouse orthologs/homologs from Ensembl, and 1,387 of them were predicted to be potentially regulated by IFN-gamma. In the pilot experiment, the regulation pattern of a subset of predicted genes that were not detected by microarray approach was evaluated by quantitative PCR. The results for the four novel genes, which are up regulated by IFN-gamma in human macrophages and identified by this approach, are described in the present communication.

Animals↗

[Performance of treatment wetland systems for surface water quality improvement].

Intercropped with Phragmites communis and Typha angustifolia, subsurface flow constructed wetland systems (CWs) with the surface area of 3 x 20m x 2m were established beside Guanting Reservoir, an important source water base of Beijing. The treatment performance of the systems with different season were studied, the impacts of influent concentration, hydraulic loading rate and water temperature on contaminations removal were analyzed. The result showed that the subsurface flow CWs had the better decontamination effect to micro-pollution surface water. The relationship between the concentrations of CODMn and NH4+ -N in inflow and outflow followed the linear equation. The removal rates of total nitrogen (TN) and total phosphorus (TP) in the systems were 20%-60% and 30%-45%, respectively. The removal rates of contaminations were reduced with the decrease of water temperature and the increase of hydraulic loading rate, the removal rates of CODMn, N4+ -N and TN showed the positive correlation with their inflow concentration, but the removal rate of TP showed the negative correlation with its inflow concentration. Operation and management considerations of the subsurface flow CWs in winter were investigated in this study.

Biodegradation, Environmental↗

[Effects of anti-CXCR4 monoclonal antibody on adhesion and proliferation of human acute myelocytic leukemia cell line HL-60].

BACKGROUND & OBJECTIVE: Stromal cell derived factor-1 (SDF-1), excreted by bone marrow stromal cells, may be involved in shielding of marrow stromal cells from leukemia cells by binding to its receptor CXCR4, but the relation between SDF-1/CXCR4 axis and leukemia cells is unclear. This study was to inhibit activity of SDF-1 by anti-CXCR4 monoclonal antibody 12G5, observe changes of adhesion and proliferation of acute myelocytic leukemia cell line HL-60 co-cultivated with leukemic marrow stromal cells, and to assay potential of inhibiting SDF-1-driven processes on treating marrow residual disease. METHODS: HL-60 cells were co-cultured with leukemic marrow stromal cells, and 10 mug/ml 12G5 was added to block SDF-1 activity. Adhesive state, adhesion rate, apoptosis rate, and cell cycle of HL-60 cells were observed after incubation. Living conditions of HL-60 cells were detected by trypan blue exclusion, cell growth curve was protracted. RESULTS: Adhesion rate of 24-h 12G5-incubated HL-60 cells was (39.4+/-7.9)%, while that of control HL-60 cells was (51.4+/-5.9)% (P< 0.05). G0/G1, S, and G2/M phases of 24-h 12G5-incubated HL-60 cells were (55.2+/-4.9)%, (30.4+/-4.1)%, and (14.4+/-5.2)%, respectively, and apoptosis rate was (9.0+/-1.7)%; while those of control HL-60 cells were (44.7+/-2.2)%, (45.3+/-3.7)%, (10.0+/-2.6)%, and (4.0+/-2.4)%, respectively. T test showed that 12G5 induced more cells entering G0/G1 phase (P< 0.05), and increased cell apoptosis rate(P< 0.05). Compared with control HL-60 cells, survival rate and proliferation of 48-h 12G5-incubated HL-60 cells decreased markedly. CONCLUSION: 12G5 may inhibit adhesion ability and proliferation of HL-60 cells, thus inhibiting SDF-1 activity by 12G5 may be helpful to the treatment of marrow residual disease.

Antibodies, Monoclonal↗

[Clinical application of composite skin graft consisting of acellular allogenic dermis and autologous skin].

OBJECTIVE: To study the procedures of applying composite skin graft consisting of acellular allogenic dermis and autologous skin in the treatment of full-thickness burns and scar formation. METHODS: Fifteen burn wounds in 8 patients were treated with the composite skin graft using one-stage grafting. RESULTS: Complete wound healing was achieved in 13 wounds. The external appearance, texture and flexibility of the grafted skin were satisfactory in most cases and no obvious scar formation was observed. CONCLUSION: One-stage grafting of the composite skin graft yields a high success rate for most burn wounds with good basal layer condition.

Adolescent↗

[Study on large-scale CD34+ cell enrichment using immunomagnetic isolation apparatus].

In order to find a method suitable for purifying large amount of CD34(+) cells, from 5 cases who accepted autologous peripheral blood stem cell transplantation, CD34(+) cells were collected and enriched by using Isolex 300i (Nexell). Phenotypes were detected by flow cytometry and the biological viability were assayed by the colony-forming experiments and cell expansion experiment in vitro. The results showed that the number of mononuclear cells first collected was about (3.5 - 6.0) x 10(10) and (0.55 - 1.2)% of cells were CD34 positive. The number of positive production was about (2.0 - 3.0) x 10(8); the CD34(+) cells purity was (75 - 85)% and the yield was (40 - 65)%. The CD34(+) cells of positive production could expand up to 2 - 3 times when cultured with SCF + IL3 + FL + TPO + EPO in vitro. The results of colony-forming experiments demonstrated that the CD34(+) cells collected has enough colony-forming ability. All results showed the enriched CD34(+) cells with biological viability. In conclusion, the CD34(+) immunomagnetic isolation apparatus Isolex300i is suitable to clinical application for a large amount of CD34(+) cell enrichment.

Antigens, CD34↗

[The relationships between biomarkers of age-related changes in bone turnover and bone mineral density in healthy Chinese women].

OBJECTIVE: To study the relationships of serum bone alkaline phosphatase (sBAP), serum osteocalcin (sOC) and the ratio of urine cross-linked N-telopeptide of collagen type I (uNTX)/creatine (Cr) with age and bone mineral density (BMD) in healthy women aged 20 - 80 years. METHODS: sBAP, sOC and uNTX were measured using ELISA. BMD at lumbar spine 1 - 4 anteroposterior (AP) and at femoral neck (FN) was studied using DXA (QDR 4500A) in 668 healthy women. Correlations of bone biomarkers with age and BMD were fitted in entire female population by ten kinds of regression models. RESULTS: (1) sBAP, sOC and uNTX were positively correlated with age (all P < 0.001). The cubic regression model was better fitted with age-related changes of bone biomarkers as compared with the other regression models and the coefficients of determination (R(2)) of fitting curve were 0.181 - 0.381 (P < 0.001). (2) When all subjects were stratified by 10-year age groups, the bone biomarker values during 30 - 39 years of age were the lowest, then they increased gradually to a highest level in the 50 - 59 years of age. (3) When subjects were stratified by menopause, levels of sBAP, sOC and uNTX in postmenopausal women with a low value of BMD at AP and FN were significantly higher than those in premenopausal women (all P < 0.001). (4) Positive correlation among sBAP, sOC and uNTX was found (all P < 0.001) and BMD values at AP and FN were negatively correlated with all the bone biomarkers (all P < 0.001). CONCLUSIONS: sBAP, sOC and uNTX may be the sensitive and relatively specific markers to evaluate age- and menses-dependent changes of bone turnover, but they are negatively correlated with BMD, suggesting that individuals with increased bone biomarker levels are associated with a decreased BMD value.

Adult↗

[Study on the Characteristics of cell cycle and proliferation of CD34+ hematopoietic stem cells in myelodysplastic syndromes].

OBJECTIVE: To study the characteristics of cell cycle and proliferation of CD34+ hematopoietic stem cells in patients with myelodysplastic syndromes (MDS). METHODS: Propidium iodide staining was used to examine cell cycle parameters (G(0)/G(1), S and G(2)/M) of bone marrow mononuclear cells (BMMNCs) while immunofluorescent double staining and FACS techniques were used to measure Ki67 expression in BM CD34+ cells from normal control, patients with MDS, acute myeloid leukemia preceded by MDS (MDS-AML) and primary AML. RESULTS: There was a statistical up-tendency in G(0)/G(1) phase proportion of BMMNCs whereas a statistical down-tendency in S and G(2)/M phase proportions among normal control, MDS and primary AML. Compared to primary AML, MDS-AML had significantly higher ratios of S (P < 0.05), G(2)/M (P < 0.05) and S + G(2)/M (P < 0.05) phase cells while lower ratio of G(0)/G(1) phase cells (P < 0.05). The proportion of CD34+Ki67+ cells in MDS patients was significantly higher than that in normal control (P = 0.004). So were the percentages of CD34+Ki67+ cells in low-risk [(0.54 +/- 0.49)%, P < 0.05] and high-risk MDS patients [(1.69 +/- 1.66)%, P = 0.022]. Furthermore, there was statistical difference between low-risk and high-risk MDS (P < 0.05). Compared to normal control and primary AML, MDS-patients had the highest proportion of CD34+Ki67+ cells [(16.75 +/- 13.58)%, P < 0.05]. The proportion of CD34+Ki67+ cells in CD34+ cells in MDS patients [(48.50 +/- 20.49)%] was significantly higher than that in normal control [(27.71 +/- 16.04)%, P < 0.01]. So were the low-risk [(51.85 +/- 21.80)%, P = 0.002] and high-risk MDS [(43.93 +/- 18.57)%, P < 0.05]. The proportion of CD34+Ki67+ cells in CD34+ cells in MDS-AML patients [(60.92 +/- 30.12)%] was the highest, and was statistically higher than that in both normal control (P < 0.01) and primary AML patients [(17.01 +/- 15.93)%, P < 0.001]. The proportion of CD34+Ki67+ cells in Ki67+ cells in MDS patients [(4.91 +/- 4.68)%, P < 0.01] was significantly higher than that [(2.43 +/- 2.37)%] in normal controls. In the low-risk MDS group it was (4.11 +/- 3.94)%, (P > 0.05) and in high-risk MDS group it was (5.76 +/- 5.38)%, (P < 0.05). CONCLUSION: High proportion of G(0)/G(1) cells and G(1) phase arrest occurred in MDS. High proliferation capacity of MDS clone, especially that derived from CD34+ cells, might play an important role in the clonal expansion, diseases deterioration and worse prognosis of MDS.

Acute Disease↗

[Changes of subsets of DC1 in the bone marrow of severe aplastic anemia patients].

OBJECTIVE: To measure the subsets of dendritic cells 1 (DC1) in the bone marrow of severe aplastic anemia (SAA) patients and evaluate the relationships between the CD11c+CD83+ cells and Th1 cells, CD3+CD8+ cells or hematopoietic function and explore the role of DC1 in the pathogenesis of SAA. METHODS: By FACS, the quantities and ratios of CD11c+CD1a+ cells, CD11c+CD83+ cells, Th1 cells, and CD3+CD8+ cells in the bone marrow of SAA patients and normal controls were detected respectively. The relationships between CD3+CD8+ cells and reticulocyte absolute value (Ret) or neutrophil absolute value (ANC), between Th1 cells and CD3+CD8+ cells, Ret or ANC, between CD11c+CD83+ cells, and Th1 cells, CD3+CD8+ cells, Ret or ANC were evaluated. RESULTS: In normal controls' bone marrow, the percentages of Th1 cells, CD11c+CD1a+ cells, CD11c+CD83+ cells and the ratio of CD11c+CD83+/CD11c+CD1a+ were (0.42 +/- 0.30)%, (0.38 +/- 0.29)%, (0.37 +/- 0.32)% and 1.07 +/- 0.10, respectively. In untreated SAA patients, they were (4.87 +/- 0.54)%, (1.73 +/- 0.24)%, (3.38 +/- 0.56)% and 2.21 +/- 0.32 respectively, which were higher than that in normal controls (P < 0.01). In recovering SAA patients, the percentages of Th1 cells, CD11c+CD1a+ cells and CD11c+CD83+ cells decreased significantly to (0.53 +/- 0.22)%, (0.61 +/- 0.23)%, (0.65 +/- 0.22)%, respectively (P < 0.01). The ratio of CD11c+CD83+/CD11c+ CD1a+ in recovering SAA patients decreased to 1.37 +/- 0.25, which was similar to that in normal controls (P > 0.05). The percentage of CD3+CD8+ cells in untreated SAA patients was (32.32 +/- 10.22)%, and in recovering SAA patients decreased to (13.67 +/- 5.24)% (P < 0.01). The percentage of CD3+CD8+ cells in SAA patients was negatively correlated with their Ret and ANC (P < 0.05), while their Th1 cell percentages were positively correlated with their CD3+CD8+ cells (P < 0.01), and negatively correlated with their Ret and ANC (P < 0.01). SAA patient's CD11c+CD83+ cell percentages were positively correlated with their Th1 cell and CD3+CD8 cells (P < 0.01, P < 0.05), but negatively with their Ret and ANC (P < 0.01). CONCLUSION: Both immature DC1 and activated DC1 increased in the bone marrow of SAA patients, and the balance of DC1 subsets shifted from stable form to active one, which might promote Th0 cells to polarize to Th1 cells, and cause the over-function of T lymphocytes and hematopoiesis failure in SAA.

Adolescent↗

[Quantitative and functional changes of T helper cell subsets in the bone marrow of severe aplastic anemia patients].

OBJECTIVE: To evaluate the quantitative and functional changes of T helper (Th) cell subsets in the bone marrow of severe aplastic anemia (SAA) patients and the relationship between these changes and the patients hematopoietic function. METHODS: By FACS, the quantity and ratio of Th1 and Th2 cells, the percentage of CD3(+)CD8(+) cells in the bone marrow were detected in 24 patients with SAA at active phase, 15 patients with SAA at recovery phase, and 16 normal controls. By radioimmunoassay, the serum levels of TNF-alpha, or IL-4 in 20 SAA patients at active phase, 12 at recovery phase and 16 normal controls were measured. The relationships between CD3(+)CD8(+) cells, TNF-alpha and Ret, ANC; and between Th1 cells and CD3(+)CD8(+) cells, TNF-alpha or Ret, ANC; between IL-4, balance of Th1/Th2 and Ret, ANC were evaluated. RESULTS: The percentages of Th1 and Th2 cells, and ratio of Th1/Th2 in bone marrow of SAA patients at active phase were (4.87 +/- 2.64)%, (0.41 +/- 0.26)% and 21.22 +/- 5.07, respectively, being higher than those of normal controls [(0.42 +/- 0.30)% (P < 0.01), (0.24 +/- 0.17)% (P < 0.05) and (1.57 +/- 0.93) (P < 0.01), respectively] and all of them reduced to normal levels of SAA at recovery phase (P > 0.05). The percentage of CD3(+)CD8(+) cells significantly decreased from (32.32 +/- 8.69)% at active phase to (13.76 +/- 2.96)% at recovery phase (P < 0.01). The serum levels of TNF-alpha and IL-4 at active phase was (4.29 +/- 3.15) microg/L and (1.24 +/- 0.73) microg/L, respectively, being higher than those of normal controls (1.21 +/- 1.16) microg/L, (1.18 +/- 0.97) microg/L, but only the difference of TNF-alpha was statistically significant (P < 0.01). In recovery SAA patients, the serum levels of TNF-alpha significantly decreased to (1.46 +/- 1.41) microg/L (P < 0.01), and the levels of IL-4 increased markedly to (3.05 +/- 1.94) microg/L. The CD3(+)CD8(+) cells and TNF-alpha of patients negatively correlated with Ret (P < 0.05; P < 0.05) and ANC (P < 0.05; P < 0.05), Th1 cells correlated with CD3(+)CD8(+) cells and TNF-alpha positively (P < 0.01; P < 0.05), the Ret and ANC negatively (P < 0.01; P < 0.01), IL-4 and the balance of Th1/Th2 positively correlated with Ret and ANC (P < 0.05, P < 0.01; P < 0.01, P < 0.01). CONCLUSION: The bone marrow failure in SAA might be caused not only by the increase of Th1 cells, Th1 type effector cells and cytokines, but also by insufficient compensation of Th2 cells and Th2 type cytokines, which shifted the balance of Th1/Th2 favorable to Th1.

Adolescent↗

[Expression of apoptosis related proteins in CD34 positive bone marrow cells of patients with polycythemia vera].

OBJECTIVE: To investigate the expression of apoptosis receptor FAS (CD95) and apoptosis related protein Bcl-2 and Bax in CD34 positive bone marrow cells of the patients with polycythemia vera (PV). METHODS: The expressions of apoptosis receptor FAS (CD95) and apoptosis related protein Bcl-2 and Bax in bone marrow CD34(+) cells from 21 PV patients, 8 essential thrombocythemia (ET) and 11 normal persons were assessed by bicolor flow cytometry (FCM), and the expressions of Bcl-2 and Bax mRNA were assessed by RT-PCR, and their correlation was analysed. RESULTS: There was no difference between the expressions of CD95 in CD34(+) bone marrow cells of PV patients (42.65 +/- 15.56)%, and that of ET patients (45.31 +/- 17.62)% and of normal person (37.55 +/- 15.19)% (P > 0.05). There was no difference between the expression of Bax in CD34(+) bone marrow cells of PV patients (35.83 +/- 9.33)% and of normal persons (41.65 +/- 9.04)% (P > 0.05). The expression of Bcl-2 in CD34(+) bone marrow cells of PV patients (79.35 +/- 14.43)% was significantly higher than that of normal controls (55.84 +/- 13.43)% (P < 0.01). The ratio of Bax/Bcl-2 of PV patients (0.47 +/- 0.14) was significantly lower than that in normal controls (0.76 +/- 0.24) (P < 0.01). The expression of Bcl-2 mRNA in PV patients' bone marrow hematopoietic cells was higher than that of normal controls (P < 0.01). There was no difference between the expression of Bax mRNA in bone marrow hematopoietic cells of PV patients and that of normal controls. Bcl-2 expression was negatively correlated with Annexin V expression in CD34(+) bone marrow cells of PV patients. CONCLUSION: Over-expression of Bcl-2, one of anti-apoptosis genes, in CD34(+) bone marrow cells might be involved in the lower apoptosis of PV patients.

Adult↗

[Characteristic of the removal of 2,4-dichlorophenol by biological activated carbon].

The adsorption characteristics and kinetics of 2,4-Dichlorophenol (2,4-DCP) by biological activated carbon (BAC) was studied through contrast experiments with conventional activated sludge alone or quartz as the carrier. The advantage and disadvantage of removing 2,4-DCP using BAC and the mechanism of this process were investigated. The results show that the method of removing 2,4-DCP by BAC is applicable in practices, and the process of BAC demonstrates high removal rate than the process of suspended activated sludge and biofilm with quartz as the carrier. In addition, the BAC process showed high resistance to shock loadings, therefore, it is suitable to be utilized at high organic loading and under long-term operation. In BAC-system, activated carbon could not only adsorb 2,4-DCP but also oxidized 2,4-DCP.

Adsorption↗

Molecular cloning and characterization of a Rac1 homologue cDNA from Trichomonas vaginalis.

OBJECTIVE: To clone and characterize a Rac1 homologue from Trichomonas vaginalis for studying cell cycle of the organism. METHODS: A cDNA library derived from T. vaginalis mRNA was constructed into lambda TriplEx2 phage vector. An expression sequence tag program was launched. Sequences of cDNA clones were analyzed using NCBI BLAST algorithms, and ClustalW and Treeview programs. RESULTS: A cDNA clone with a length of 714 base pairs was isolated. The sequence analysis showed that the cDNA clone has an open reading frame with 600 bp. The deduced amino acid sequence from the open reading frame contains 200 residuals and is most homologous to Rac1 subfamily of Rho GTPases with >60% identity. The conserved sequence elements of Rho GTPases, such as GTP-binding sites, GTPase-activating protein (GAP) interaction motifs, GTP-dissociation inhibitors (GDI) interaction motifs, guanine nucleotide exchange factor (GEF) interaction elements, etc, were detected in the amino acid sequence. The phylogenetic analysis showed that the cDNA clone is grouped in the Rac subfamily and is more closely related to Rac1 proteins of protozoa. CONCLUSION: The cDNA clone isolated belongs to Rac subfamily of Rho GTPases and is probably a Rac1 protein of T. vaginalis.

Amino Acid Sequence↗

[Inhibition of TGFbeta1 expression in human peritoneal mesothelial cells by pcDU6 vector mediated TGFbeta1 shRNA].

OBJECTIVE: To investigate the influence of vector plasmid containing the shRNA of TGFbeta1 on the TGFbeta1 expression in human peritoneal mesotnelial cells. the TGFbeta1 expression in human peritoneal mesothelial cells (HPMCs) by a vector plasmid containing the shRNA of TGFbeta1. METHODS: The 2 selected fragments of coding sequence contained 21 nts, starting with ggcc. Two pairs of oligos were designed for these two fragments. After annealing double stranded DNA formed, they were ligated to plasmid pcDU6 (pcDNA3.1(-) with U6 promoter) separately. The inverted motif contained 6 spacer and 4 Ts, which made it possible to form short hairpin RNA. Human peritoneal mesothelial cells were isolated from human omental specimens by trypsin disaggregation to establish a stable culture model. Plasmid pcDU6 mediating the expression of TGFbeta1 and plasmid pcDNA3.1(-) mediating the expression of antisense TGFbeta1 RNA were transfected into the third passage HPMCs stimulated by 4. 25% D-glucose and lipopolysaccharide (LPS, 10 microg/ml) by lipofectamine 2000. The semi-quantification reverse transcriptive PCR (RT-PCR) was performed to detect the expression of TGFbeta1 mRNA. The TGFbeta1 level in the culture supernatant was measured with a sandwich enzyme-linked immunosorbent assay. RESULTS: The expression of TGFbeta1 was upregulated significantly in HPMCs stimulated by 4.25% D-glucose and LPS (P < 0.01). Both RT-PCR and ELISA showed that pcDU6 vector plasmid mediated TGFbeta1 shRNAs inhibited the expression of TGFbeta1 in HPMCs significantly (P < 0.01). pcDNA3.1(-) plasmid mediated antisense TGFbeta1 RNA did not remarkably inhibit the expression of TGFbeta1 in HPMCs compared with the pcDU6 group (P > 0.05). pcDU6 vector plasmid mediated TGFbeta1 shRNAs may significantly down-regulated the expression of TGFbeta1 in HPMCs compared with the pcDNA3.1(-) plasmid mediated antisense TGFbeta1 RNA (P < 0.01). There was no difference in the expression of TGFbeta1 between the 2 pcDU6 vector plasmid mediated TGFbeta1 shRNAs (P > 0.05). CONCLUSION: pcDU6 vector plasmid mediated shRNAs may inhibit the expressin of TGFbeta1 in HPMCs stimulated by 4.25% D-glucose and LPS, suggesting the possible efficacy of pcDU6 vector plasmid mediated shRNA in preventing peritoneal fibrosis in patients receiving peritoneal dialysis.

Cells, Cultured↗

[Garlicin and formocresol in the treatment of chronic periapical periodontitis].

OBJECTIVE: To evaluate the short period clinical responses after sealed garlicin and formocresol small cotton ball in the root canal entrance to treat chronic periapical periodontitis. METHODS: Treatment records of 185 teeth with chronic periapical periodontitis were compared. Of them, 94 teeth were treated by sealed small garlicin cotton ball in the root canal entrance, 78 were treated by sealed small formocresol cotton ball in the root canal entrance, and the other 13 were treated by sealed small normal saline cotton ball. The curative effects were evaluated through clinical observation. RESULTS: The ratios of acute reaction in 3 days following sealed garlicin, formocresol and normal saline small cotton ball were 5.1%, 10.7%, and 50% in the anterior teeth, and 5.5%, 8.0%, and 60%, in the posterior teeth, respectively. CONCLUSION: The clinical curative effects were similar between garlicin and formocresol in the short period. Formocresol can be substituted by garlicin.

Adolescent↗

Induced antitumor immunity against DMBA-4 metastatic mammary tumors in rats using laser immunotherapy.

Induced antitumor immunity is a highly effective and long-term cure for cancer, particularly for metastatic tumors. Laser immunotherapy was developed to induce such an immunologic response. It involves intratumoral administration of a light-absorbing dye and a specially formulated immunoadjuvant, followed by noninvasive irradiation of a near-infrared laser. Treatment of DMBA-4 metastatic mammary tumors in rats with this approach has resulted in local control of primary tumors and eradication of untreated distant metastases. After laser immunotherapy, rats were resistant to tumor rechallenge and developed immunity, which could be adoptively transferred. To better understand the immunity induced in this tumor model, immunization using freeze-thaw DMBA-4 cell lysates was performed, followed by tumor challenge 21 days later. Tumor cell lysate immunization delayed the emergence of metastases but did not provide immunity against the tumor challenge. Also performed was surgical resection of primary tumors before the observation of metastatic tumors. Removal of primary tumors was unsuccessful at changing the course of tumor progression. Tumors re-emerged at the primary sites, and metastases developed at multiple remote sites. In contrast, tumor-bearing rats successfully treated by laser immunotherapy experienced tumor regression and eradication and developed strong resistance to repeated challenges by tumor cells of the same type. Our results show that laser immunotherapy could have potential for the treatment of metastatic tumors by inducing tumor-specific, long-lasting immunity.

9,10-Dimethyl-1,2-benzanthracene↗

Seed dispersal by the Florida box turtle (Terrapene carolina bauri) in pine rockland forests of the lower Florida Keys, United States.

Seed dispersal by animals is one of the most important plant-animal mutualisms, but saurochory, the dispersal of seeds by reptiles, has received little attention. We investigated the role of the Florida box turtle (Terrapene carolina bauri) as a seed dispersal agent in pine rockland forests of the lower Florida Keys and examined the effect of turtle digestion on seed germination. We obtained seeds of 11 species with fleshy fruits and 2 species with non-fleshy fruits (a grass and legume) from the feces of 145 box turtles collected on Key Deer National Wildlife Refuge from 1999 to 2000. We planted the seeds of nine species and germination percentage (percentage of seeds that germinated during the experiment) varied from 10% to 80%. Comparative germination experiments were conducted with Thrinax morrissii, Serenoa repens, and Byrsonima lucida. We compared the germination percentage and germination rate (number of days from planting to seedling emergence) of seeds from three treatments (seeds recovered from feces, control seeds with pulp, and control seeds without pulp) and continued these experiments for up to 2 years. Passage through the box turtle digestive tract greatly enhanced the germination percentage and germination rate of S. repens, but decreased the germination percentage of B. lucida and T. morrissii, and decreased germination rate for T. morrissii. Subsequent destructive seed viability tests revealed that many ungerminated T. morrissii seeds remained viable, suggesting long-term seed dormancy may occur, even after passage through the turtle digestive system. In addition, the proportion of ungerminated seeds which remained viable was greater for seeds recovered from turtle feces than from control seeds with pulp. Furthermore, removal of fleshy pulp either manually or by the turtle digestive system may allow T. morrissii to escape insect predation.

Animals↗

Paradoxical action of fulvestrant in estradiol-induced regression of tamoxifen-stimulated breast cancer.

BACKGROUND: Long-term tamoxifen treatment of breast cancer can result in tamoxifen-stimulated breast cancer, in which estrogen inhibits tumor growth after tamoxifen withdrawal. We investigated the molecular mechanism(s) of estradiol-induced tumor regression by using an in vivo model of tamoxifen-stimulated human breast cancer. METHODS: Growth of parental estradiol-stimulated MCF-7E2 and long-term tamoxifen-stimulated MCF-7TAMLT xenografts in athymic mice was measured during treatment with vehicle, estradiol, estradiol plus tamoxifen, tamoxifen alone, estradiol plus fulvestrant, or fulvestrant alone. Apoptosis was detected by the terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. Protein expression was assessed by western blot analysis. mRNA expression was assessed by real-time reverse transcription-polymerase chain reaction. All statistical tests were two-sided. RESULTS: MCF-7E2 tumor growth was stimulated by estradiol (cross-sectional area at week 13 = 1.06 cm2, 95% confidence interval [CI] = 0.82 to 1.30 cm2; P<.001) compared with control (0.06 cm2, 95%CI = -0.02 to 0.14 cm2), but tumor growth was inhibited by tamoxifen or fulvestrant. MCF-7TAMLT tumor growth was stimulated by tamoxifen) cross-sectional area at week 10 = 0.60 cm2, 95% CI = 0.50 to 0.70 cm2; P<.001) compared with control (0.02 cm2, 95% CI = 0.00 to 0.04 cm2). For MCF-7TAMLT tumors that were initially 0.35 cm2, estradiol-induced regression to 0.18 cm2 (95% CI = 0.15 to 0.21 cm2; P<.001), and tamoxifen or estradiol plus fulvestrant enhanced tumor growth to 1.00 cm2 (95% CI = 0.88 to 1.22 cm2). Estradiol increased the number of apoptotic cells in tumors by 23% (95% CI = 20% to 26%; P<.001) compared with all other treatments, decreased estrogen receptor alpha(ERalpha) protein expression, increased the expression of Fas mRNA and protein, decreased the expression of HER2/neu mRNA and protein and nuclear factor kappaB (NF-kappaB) protein but did not affect Fas ligand protein expression compared with control. Paradoxically, fulvestrant reversed this effect and stimulated MCF-7TAMLT tumor growth apparently through ERalpha-mediated regulation of Fas, HER2/neu, and NF-kappaB. CONCLUSION: Physiologic levels of estradiol induced regression of tamoxifen-stimulated breast cancer tumors, apparently by inducing the death receptor Fas and suppressing the antiapoptotic/prosurvival factors NF-kappaB and HER2/neu.

Animals↗