用胞变换法分析分段线性系统周期运动稳定性

本文首先简单介绍了胞变换法,并提出了加工绘图数据的一种算法,这种算法节省机时和存贮绘图数据所需的空间,使绘制各种吸引域图形成为可能。然后利用胞变换法对具有分段线性非线性特征的弹簧摇床的全局性态进行了分析研究,并用计算机模拟出该系统存在的各种周期运动的时间历程曲线及相应的周期运动的吸引域。论文分析了弹簧摇床五种阻尼参数下全局性态,得出了该类系统周期运动稳定性和阻尼之间的关系。

Cell Cycle Kinetic Analysis in the Cortical Regions of the Lentil Primary Root During Germination

Cell cycle kinetic activity in the cortical cells of the lentil (Lens culinaris Me-die. cv. Verte du Puy) primary root during germination was examined both temporally and spatially. Immunohistochemical and cytological evidence indicated that DNA replication and cell division started in the cortical cells of tire lentil primary root after around 13 and 17 h of imbibition, respectively. The first cells in DNA synthesis and the First mitotic figures all appeared in the cortical cells about I mm front the root-cap junction, but these divided cells had synthesized their DNA during the maturity of seed instead of during germination. The kinetic pattern of activity of the first cell cycle showed that these cells were not activated synchronously, but re-entered the cell cycle in turn depending on their places in the root tip, However, the adjacent cells partially synchronously proceeded their cell cycle.

Epigenetic modification regulates both expression of tumor-associated genes and cell cycle progressing in human colon cancer cell lines: Colo-320 and SW1116

The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established human colon cancer cell lines: Colo-320 and SW1116. Treatments with 5-aza-2'-deoxycytidine (5-aza-dC) and trichostatin A, alone or in combination, were applied respectively. The methylation status of the CDKN2A promoter was determined by methyla-tion-specific PCR, and the acetylated status of the histones associated with the p21WAF1 and CDKN2A genes was examined by chromatin immunoprecipitation. The expression of the CDKN2A, p21WAF1, p53, p73, APC, c-myc, c-Ki-ras and survivin genes was detected by real-time RT-PCR and RT-PCR. The cell cycle profile was established by flow cytometry. We found that along with the demethylation of the CDKN2A gene promoter in both cell lines induced by 5-aza-dC alone or in combination with TSA, the expression of both CDKN2A and APC genes increased. The treatment of TSA or sodium butyrate up-regulated the transcription of p21WAF1 significantly by inducing the acetylation of histones H4 and H3, but failed to alter the acetylation level of CDKN2A-associated histones. No changes in transcription of p53, p73, c-myc, c-Ki-ras and survivin genes were observed. In addition, TSA or sodium butyrate was shown to arrest cells at the G1 phase. However, 5-aza-dC was not able to affect the cell cycle progression. In conclusion, regulation by epigenetic modification of the transcription of tumor-associated genes and the cell cycle progression in both human colon cancer cell lines Colo-320 and SW1116 is gene-specific.

The expressions of Pin1, β-catenin and cyclin D1 in elderly lung carcinomas and their significance

Objective： To investigate the expressions and correlations of Pin1, β-catenin and cyclin D1 in elderly lung carcinomas. Methods： The expressions of Pin1, β-catenin and cyclin D1 were examined in the specimens of 92 elderly lung carcinomas and 10 normal lung tissues by immunohistochemistry and explored the relationship between the expression levels and clinicopathological factors. Results： （1） The overexpression of Pin1 and cyclin D1 in lung carcinomas was 46 （50%） cases and 60 （65.22%） cases respectively and 56 （60.82%） cases showed positive immunoreactivity for 13-catenin in the nuclear and （or） cytoplasmic fraction in tumor tissues. In normal tissue, the expressions of Pin1 and cyclin D1 were negative, the expression of β-catenin was lied in cell membrane. （2） In lung carcinomas the expressions of Pin1, β-catenin and cyclin D1 correlated with tumor differentiation （P 〈 0.05）. The pesitive expression rate and intensity of Pin1 correlated with tumor stage （P = 0.032） and lymph node positive disease （P = 0.041）. The expression of β-catenin correlated with lymph node positive disease （P = 0.012）. （3） High expression levels of Pin1 correlated with aberrant I]-catenin expression （P = 0.000） but did not show a correlation with cyclin D1 （P = 0.157）. Conclusion： In elderly lung carcinomas, the positive expression of Pin1 causes abnormal accumulation of β-catenin and actives its target gene, however, this target gene was not cyclin DI. The detection of Pin1 expression had some clinical significance in estimating prognosis of elderly patient with lung carcinomas.

Clinicopathologic features of 112 cases with mantle cell lymphoma

Objective： This study aims to explore the clinicopathologic features of 112 patients with mantle cell lymphoma （MCL）. Methods： Data from 112 MCL cases were collected, and immunohistochemical assay was conducted. Fluorescence in situ hybridization （FISH） detected a break in the CCND 1 gene. The t-test was used in the statistical analysis. Results： All tumor cells in the 112 cases expressed B cell-related antigen, including 1 blastoid subtype and 1 polymorphic subtype. Among all cases, 106 expressed CD5 and 104 expressed cyclin D1. A break in the CCND1 gene was not found in 3 cases with CDS-MCL. IgH/CCND 1 polyploid was observed in 2 classic cases. Conclusion： MCL is a type of special immunophenotypic B-cell lymphoma, The prognoses ofblastoid and polymorphic subtypes are poor. Special subtypes should be classified during diagnosis.

Expression and significance of cyclin E in gastric carcinoma

Objective:The aim of the study was to investigate the expression and significance of cyclin E in gastric carcinoma.Methods:We detected the expression of cyclin E in three different pathologic types gastric carcinoma samples by immuno-histochemical staining technique (SP method).Results:In 59 gastric carcinoma samples the positive rate of cyclin E expression in gastric carcinoma was 55.93% (33/59), and it was significantly higher than that of normal gastric mucosa (10.53%, 2/19).The positive rates of cyclin E expression in poor differentiation group and mucoid carcinoma group were 68.75% (11/16) and 66.67% (16/24), respectively, and these were significantly higher than that in well-middle differentiation group (31.58%, 6/19), but there was no significant difference between the fronted two groups (P>0.05).Conclusion:The high expression of cyclin E is associated with the progression of gastric carcinoma and probably related to the behavior of cellular biology.

BmCyclin B and BmCyclin B3 are required for cell cycle progression in the silkworm, Bombyx mori

Cyclin B is an important regulator of the cell cycle G2 to M phase transition. The silkworm genomic database shows that there are two Cyclin B genes in the silkworm (Bombyx mori), BmCyclin B and BmCyclin B3. Using silkworm EST data, the cyclin B3 (EU074796) gene was cloned. Its complete cDNA was 1665 bp with an ORF of 1536 bp derived from seven exons and six introns. The BmCyclin B3 gene encodes 511 amino acids, and the predicted molecular weight is 57.8 kD with an isoelectric point of 9.18. The protein contains one protein damage box and two cyclin boxes. RNA interference-mediated reduction of BmCyclin B and BmCyclin B3 expression induced cell cycle arrest in G2 or M phase in BmN-SWU1 cells, thus inhibiting cell proliferation. These results suggest that BmCyclin B and BmCyclin B3 are necessary for completing the cell cycle in silkworm cells.