Value of detecting p16 gene methylation in the diagnosis of malignant pleural effusion / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate aberrant methylation in the promoter of p16 gene in the sediment cells of pleural effusion and evaluate its clinical significance in the differentiating benign and malignant pleural effusion.</p><p><b>METHODS</b>Using methylation-specific PCR (MSP), aberrant promoter methylation of p16 gene was detected in the sedimental cells of pleural effusion samples from 66 patients with pleural effusion.</p><p><b>RESULTS</b>Of the 66 patients with pleural effusion, 36 had a definite diagnosis of malignant pleural effusion, and the rest were confirmed to have benign pleural effusion. The positivity rate of p16 gene promoter methylation was 69.4% (25/36) in malignant pleural effusion and 13.3% (4/30) in benign pleural effusion specimens, showing a significant difference between them (χ² = 20.915, P < 0.01). The diagnostic sensitivity, specificity and accuracy of aberrant promoter methylation of p16 gene in the 36 malignant cases were 69.4%, 86.7% and 77.3%, respectively. The positive expression of p16 gene promoter methylation in malignant pleural effusion was not correlated to the histological type or the pathological grade of the tumor (P > 0.05).</p><p><b>CONCLUSION</b>Detection of aberrant methylation in p16 gene promoter in the sediment cells of pleural effusion specimens by MSP method allows differentiation between benign and malignant pleural effusion.</p>

ID4 methylation patterns in childhood T line and B line lymphocytic leukemia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the relationship of methylation of inhibitor of DNA binding 4 (ID4) gene core promoter region with childhood T line, B line and T/B acute lymphocytic leukemia (ALL).</p><p><b>METHODS</b>Methylation-specific polymerase chain reaction (MS-PCR) was used to detect the methylation status of ID4 promoter region in 18 children with newly-diagnosed ALL (2 cases of T-ALL, 13 cases of B-ALL and 3 cases of T/B-ALL). Thirty-four hospitalized children with non-tumor disease served as the control group.</p><p><b>RESULTS</b>The complete methylation rate of ID4 gene promoter region (15/18, 83%) was significantly higher than the partial methylation rate (3/18, 17%) in the 18 ALL children (P<0.05). The complete methylation rate of ID4 gene promoter region in children with T-ALL, B-ALL and T/B-ALL (50%, 85% and 100% respectively) was significantly higher than that in the control group (18%; P<0.05). In contrast, the partial methylation rate and non-methylation rate in the three ALL groups were significantly lower than those in the control group (P<0.05). There were no statistically significant differences in the methylation patterns among the B-ALL, T-ALL and T/B-ALL cases.</p><p><b>CONCLUSIONS</b>The methylation of ID4 promoter region may be related to the pathogenesis of childhood ALL. The methylation patterns of ID4 promoter region are identical in B-ALL, T-ALL and T/B-ALL.</p>

Proliferation apoptotic influence of crocin on human bladder cancer T24 cell line / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the proliferation, apoptosis and mechanisms on T24 cell of transitional cell carcinoma of bladder (TCCB) by crocin.</p><p><b>METHOD</b>MTT assay was used to evaluate the proliferation of T24 cells. The changes of cell cycle and cell apoptotic percentage were measured by flow cytometry. T24 cells were inoculated into BALB/c nude mice to establish model of carcinoma of bladder. The mice were randomly divided into control group and experimental group. After treatment with 50 mmol x L(-1) crocin, the inhibited growth of tumor was observed. Electronic microscope was used to observe the morphological changes. The expressions of Bcl-2, Bax, Survivin and Cyclin D1 were detected by immunohistochemistry.</p><p><b>RESULT</b>The growth of T24 cells was remarkably inhibited after treatment of crocin. Flow cytometric profiles revealed that crocin led to the increase of the cells in G0/G1 phase, the percentage of cell apoptosis was also increased. Crocin could inhibit the growth of BALB/c xenograft tumor. The morphology changes of cell apoptosis were observed. Bcl-2, Cyclin D1 and survivin expressions determined by immunohistochemical staining were down-regulated after treatment with Bax expression up-regulated.</p><p><b>CONCLUSION</b>Crocin exerts both in vitro and in vivo anti-cancer effect on TCCB T24 cell line. The mechanisms may change tumour cell cycle and induce tumour cell apoptosis by down-regulating the expression of Bcl-2, Survivin, Cyclin D1 and up-regulating the expression of Bax.</p>

Recovery of platinum with immobilized Citrobacter freudii XP05 biomass / 生物工程学报

The objective of this work was to develop a valuable adsorbent for recovery of platinum by studying the properties of Pt4+ -adsorption with immobilized Citrobacter freudii XP05 biomass. Five methods for immobilization of Citrobacter freudii XP05 biomass were compared. The method with gelatin-alginate sodium as entrapment matrix was considered to be the optimal. Spherical and uniform beads were produced and the SEM micrograph indicated that the cell of strain XP08 were uniformly dispersed within the matrix. The adsorption of Pt4+ by immobilized XP05 biomass was affected with adsorptive time, pH value of the solution, immobilized biomass concentration, Pt4+ initial concentration The adsorption was a rapid process. The optimal pH value for Pt4+ adsorption was 1.5, and its adsorptive capacity increased linearly with increasing Pt4+ initial concentrations in the range of 50 - 250 mg/L. The experimental data could be fitted to Langmuir and Freundlich models of adsorption isotherm. The adsorptive capacity reached 35.2 mg/g under the conditions of 250 Pt4+ mg/L, 2.0 g/L immobilized biomass, pH 1.5 and 30 degrees C for 60 min. 98.7% of Pt4+ adsorbed on immobilized biomass could be desorbed with 0.5 mol HC1/L. The characteristics of dynamic adsorption and desorption of immobilized XP05 biomass in packed-bed reactor were investigated. The saturation uptake was 24.66 mg Pt4+ /g under the conditions of flow rate 1.2 mL/min, pH 1.5, 50 mg Pt4+/L and 1.85 g biomass(dry weight) . Adsorptive efficiency of Pt4 + by the immobilized XP05 biomass was above 78% for 4 cycles of adsorption and desorption. The recovery of platinum from waste platinum catalyst was studied. The adsorptive capacity was 20.94 mg Pt4+/g immobilized biomass under the conditions of 4.0 g/L immobilized XP05 biomass, 117.76 mg Pt4+/L and pH 1.5 for 60 min. The immobilized XP05 biomass is potentially applicable to the recovery of platinum from waste and wastewater containing platinum.