Antitumor effect of chlorophyllin in vitro

AIM: To study the effect and mechanism of chlorophyllin (CHL) inhibiting HT29 cells. METHODS: IC₅₀ value and growth curve of HT29 cells were detected with MTT method. Apoptosis was detected with Wright-Giemsa staining, FCM and DNA electrophoresis. Telomerase was detected by PCR-ELISA, and protein and mRNA expression of COX-2 gene were detected through RT-PCR and Western blot. RESULTS: CHL inhibited the growth of HT29 in a dose-dependent manner. CHL blocked HT29 cells in G₁ phase but did not induce apoptosis. Different concentration of CHL inhibits the expression of telomerase and COX-2 in HT29 cells. CONCLUSION: CHL inhibited the growth of HT29 cells by inhibiting the expression of telomerase and COX-2 and blocking cells in G₁ phase.     

Effects of fosinopril,captopril and valsartan on the expressionof tissue factor in human monocytes

AIM: To investigate the effects of angiotensin-converting enzyme inhibitors (ACEI), fosinopril, captopril and angiotensin II AT₁ antagonists, valsartan on tissue factor (TF) expression on monocytes induced by lipopolysaccharide (LPS). METHODS: Mononuclear leukocytes from normal delivered female umbilical veins were incubated with bacterial LPS in presence or absence of different ACE inhibitors .At the end of incubation, the cells were disrupted by 3 freeze-thaw cycles. TF procoagulant activity was assessed by a one-stage clotting assay. RT-PCR was used to check TF mRNA expression, and GAPDH mRNA was used for parallel assay. RESULTS and CONCLUSION: The results showed that increased expression of TF mRNA induced by LPS was inhibited by fosinopril, captopril and valsartan, respectively, and the procoagualant activity of monocytes was also reduced.     

Effect of weaver gene on biology function of CAD cells

AIM:To assess the impact of weaver gene on neuronal development, protein expression and vitality. METHODS: DNA encoding the wild-type and mutant ion channel was introduced into immortalized tyrosine hydroxylase-positive CNS-derived neurons named CAD(Cath.a-differentiated, a variant of Cath.a. Cath.a was established by targeted oncogenesis in transgenic mice) cells. DNA clone, immunostaining and Western blotting were used. Three different concentrations (0.25 mg/L, 0.5 mg/L, or 1.0 mg/L) of Girk2 and wvGirk2 expression plasmids were transfected into the CAD cells. The number of transfected cycling cells, protein synthesis and neurites growth were observed between two groups. RESULTS:The number of transfected cycling CAD cells with high concentration of wvGirk2 reduced to about 60%, compared to Girk2-transfected cells. Low concentration of wvGirk2 did not cause cell death but reduced the protein production of transfected genes. Neurite growth was also affected by wvGirk2. MK-801 and Kir2.3 altered the effect of wvGirk2. CONCLUSION:The results indicate that wvGirk2 functions as a blocker in weaver animals, which blockes the wvGirk2 channel to rescue the cells from death. Our data also suggest that the presence of channels and the level of wvGirk2 may have a significant impact on the fate of cells containing wvGirk2.     

应激诱导对蓝狐自咬症及血清生化指标的影响

本研究模拟蓝狐在饲养管理过程中的不良环境,结合10种血清生化指标研究环境应激对蓝狐自咬症发生的影响。选用体重相近的健康蓝狐90只(公母各半),其中试验组60只,对照组30只。采用摇床、转移栋舍、限制、拥挤、饥饿、休息等6种不同的应激诱导方式对蓝狐进行应激诱导,结果显示,应激诱导持续30 d,试验组血清中GPT、ALP、GSH-Px和CAT活性极显著低于对照组(P＜0.01),MDA含量显著低于对照组(P＜0.05),SOD活性极显著高于对照组(P＜0.01);应激诱导60 d,ALP、CK、GSH-Px、CAT和MDA活性极显著高于对照组(P＜0.01),SOD活性极显著低于对照组(P＜0.01),GPT活性显著低于对照组(P＜0.05);GOT、LDH、GLU活性在整个应激诱导过程中没有显著差异(P＞0.05)。应激诱导组与对照组蓝狐自咬症发病率没有显著差异(P＞0.05),一般的环境应激对蓝狐自咬症的产生没有明显影响。     

哺乳动物体细胞克隆技术应用的研究进展

哺乳动物体细胞克隆技术是一项高新的生物技术,这一技术不仅为许多学科发展带来了机遇,它的应用将给畜牧业生产、转基因动物和医学带来了革命性的变化。作者就这几个方面的应用做一简要综述。     

Methylation of p15INK4B gene and its mechanism in patients with myelodysplastic syndrome and leukemia

AIM: To explore the relationship between hypermethylation of p15INK4B gene and the pathogenesis of hematopoietic malignances. METHODS: The expression and methylation of p15INK4B gene and the expression of DNA methyltransferase genes (DNMTs) in bone marrow cells from 54 cases with hematopoietic malignances were detected by RT-PCR, Western blot, and methylation-specific PCR. RESULTS: The p15INK4B gene was methylated more often in high-risk myelodysplastic syndrome (MDS) patients, patients at blast phase of chronic myeloid leukemia (CML-BP) and acute leukemia patients than that in low-risk MDS patients (P<0.01). The expression levels of DNMT_3A and DNMT_3B in acute leukemia patients, high-risk MDS patients, and CML-BP patients were higher than that in low-risk MDS patients (P<0.05). CONCLUSION: The hypermethylation of p15INK4B gene may be one of the most common genetic event in pathogenesis of acute leukemia, high-risk MDS, and blast phase of chronic myeloid leukemia. Furthermore, DNMT_3A and DNMT_3B are substantially over-expressed in the bone marrow cells of these patients.     

Quantification of within‐season focal spread of wheat take‐all in relation to pathogen genotype and host spatial distribution

Within season gradient of wheat take‐all was measured in field experiments according to line or random sowing host spatial distribution, and two Gaeumannomyces graminis var. tritici (Ggt) isolates (G1i and G2i), representative of the G1 and G2 genotype groups in terms of aggressiveness. Root disease incidence and severity were assessed at six dates from early March to late June on plants located at regular distances from the inoculum sources. Simple models relating disease intensity at different levels of hierarchy fitted observed data well, and indicated a strong disease aggregation both within and among plants. Disease severity on source plants placed nearby the inoculum source increased over time, ranging from 5 to 46% at the first assessment, and from 55 to 98% at the last assessment, being in general larger for G2i than G1i. In line‐sown plots, disease progressed steadily along the line but did not extend beyond 20 cm, seldom reaching the neighbour line. Disease rarely reached 25 cm in the direct‐seeded crop stands. These results indicate that Ggt intensifies but does not spread to a large extent during a cropping season. Distance from the source, pathogen genotype and assessment date had a significant effect on disease severity according to mixed model analyses, disease spread being larger for G2i than G1i. However, no significant effect of host spatial distribution could be detected. Yield loss within 20 cm of the source plant ranged between 20 and 40%, and was not significantly affected by pathogen genotype or host spatial distribution.     

Changes of plasma and myocardial calcitonin gene-related peptide in myocardial stunning rats

AIM: To investigate changes of calcitonin gene-related peptide(CGRP) in myocardial stunning rats. METHODS: Rat in vivo myocardial stunning model was used. CGRP content in plasma and myocardium were determined by radioimmunoassay. RESULTS: Plasma level of CGRP increased significantly (P＜0.01), but in left ventricular myocardium CGRP decreased obviously (P＜0.05) in myocardial stunning group compared with the control group. CONCLUSION: CGRP content in the left ventricular myocardium was negatively correlated with plasma CGRP.     

Role of androgen receptor in prostate cancer cell proliferation by use of RNAi

AIM: To study the role of androgen receptor (AR) in hormone-dependent and hormone-independent prostate cancer cell proliferation by knocking down AR expression with adenovirus-delivered siRNA. METHODS: Four well-designed siRNAs were synthesized and inserted into the adenovirus plasmid pShuttle-H1-Ri. The recombinant pShuttle-H1-Ri-AR plasmid was then co-transfected with pcDNA-AR to HEK293 cell line and Western blot was used to detect the inhibitory efficiency of different siRNAs on AR expression. Recombinant adenovirus containing more efficient siRNAs were prepared and used to infect three different humane prostate cancer cell lines including LNCap、C4-2B and CWR22Rv1. The efficiency of knocking down AR expression was detected by Western blot. The effect of AR-knocking down on cell proliferation was detected by MTT colorimetric assay. RESULTS: All of the four designed siRNAs could knock down AR expression in transient co-transfection. Infecting with recombinant adenovirus containing more efficient siRNAs in hormone-dependent and hormone-independent prostate cancer cell lines specifically knocked down AR expression with high efficiency. Knocking down AR expression significantly decreased the proliferation rate in all these prostate cancer cells. CONCLUSION: The suppressed expression of AR in prostate cell lines mediated by siRNA could efficiently inhibit the cell proliferation, and these results show that AR plays an important role in the proliferation of hormone-dependent and hormone-independent prostate cancer cells. AR is an important therapeutic target for the treatment of prostate cancer.