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排序方式: 共有401条查询结果,搜索用时 46 毫秒
1.
Increased expression of telomerase RNA component is associated with increased cell proliferation in human astrocytomas. 总被引:7,自引:1,他引:7 下载免费PDF全文
P. Sallinen H. Miettinen S. L. Sallinen H. Haapasalo H. Helin J. Kononen 《The American journal of pathology》1997,150(4):1159-1164
Deregulation of telomerase, a ribonucleoprotein polymerase that compensates progressive loss of telomeric (TTAGGG)n repeats during DNA replication, has been suggested to facilitate tumorigenesis and cellular immortality by providing unlimited proliferation capacity for cancer cells. We investigated the relationship between tumor proliferation activity and in situ expression of the telomerase RNA component in 46 human grade I to IV astrocytomas. Heterogeneously distributed telomerase RNA expression was detected from all of the tumor samples as well as from normal human brain tissue. However, expression of telomerase RNA was significantly increased in highly malignant tumors (P = 0.024) and in tumors that showed increased proliferation activity determined by MIB-1 immunohistochemistry (P = 0.014). Interestingly, increased telomerase RNA levels were observed in a subgroup of grade II astrocytomas that showed significant increase in proliferation activity (P = 0.047), indicating that the telomerase RNA component is up-regulated already in early states of astrocytoma malignancy. Telomeric repeats amplification assays revealed telomerase activity in 4 of 6 glioblastomas and in 1 rapidly proliferating grade II astrocytoma. These results suggest that increased tumor proliferation activity triggers telomerase activation via mechanisms that involve increased production of the telomerase RNA component. 相似文献
2.
Korja M Finne J Salmi TT Haapasalo H Tanner M Isola J 《Journal of clinical pathology》2005,58(7):762-765
AIMS: Neuroblastic tumours (NTs) have been shown to respond to imatinib treatment in vivo and in vitro, possibly via inactivating the c-kit receptor. The purpose of this study was to identify gastrointestinal stromal tumour (GIST)-type c-kit gene associated mutations in exons 9, 11, 13, and 17 in NTs to recognise a subset of tumours that would probably respond to imatinib treatment. METHODS: Expression of the c-kit protein was detected immunohistochemically in a total of 37 archival paraffin wax embedded NTs using polyclonal rabbit antihuman c-kit antibody. After immunohistochemistry, c-kit gene associated chromosomal mutations in all cases of NT were detected with denaturing high performance liquid chromatography (HPLC). RESULTS: Denaturing HLPC analysis did not reveal GIST-type mutations in four immunohistochemically detected c-kit positive or in 33 c-kit negative NTs. CONCLUSIONS: c-kit receptor expression and GIST-type c-kit gene mutations are rare events in NTs. Oncogenic activation of c-kit in NTs presumably differs from that of GISTs, which may influence their responsiveness to imatinib treatment. Whether c-kit has an essential role in the pathogenesis of NTs remains to be investigated. 相似文献
3.
Factors related to postmenopausal muscle performance: a cross-sectional population-based study 总被引:2,自引:0,他引:2
Sirola J Rikkonen T Kröger H Honkanen R Tuppurainen M Airaksinen O Saarikoski S 《European journal of applied physiology》2004,93(1-2):102-107
The aim of the present study was to investigate cross-sectionally the association of postmenopausal muscle strength with simple performance tests. A random sample of 1,166 naturally postmenopausal women (born 1932–1941) was selected from the Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) study cohort. Grip and quadriceps strength were measured with strain gauge dynamometers and reported in both absolute values (KPa and kg) and per kilogram of body mass (N cm–2 kg–1 and N kg–1). In addition, two performance tests, ability to stand on one foot and ability to squat down to touch the floor were carried out. A five-category self-assessment of overall health (very good, good, moderate, bad, and very bad) was obtained by postal questionnaire. The women that were able to stand on one foot and able to squat down to touch the floor had greater grip and quadriceps strength than their counterparts (P<0.001 and P<0.03 in ANOVA, respectively). In addition, self-assessed health had a strong positive association with muscle strength in the grip and leg extensor muscles in ANOVA (P<0.001 between very good and moderate or poorer state of health) and regression model (P<0.001). Adjustment for age, duration of menopause, body mass, height, physical activity level, use of HRT, and number of diseases and medications did not change any of the main effects. Also, there were no differences in results between absolute measurement values and values reported per kilogram of body mass. According to the present study, a simple performance test may be useful in the prediction of postmenopausal muscle strength. Furthermore, self-assessed state of health is strongly associated with muscle strength in postmenopausal women. 相似文献
4.
Short DNA sequences and bacterial DNA induce esophageal,gastric, and colorectal cancer cell invasion
Joonas H. Kauppila Tuomo J. Karttunen Juha Saarnio Pia Nyberg Tuula Salo David E. Graves Katri S. Selander 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2013,121(6):511-522
Toll‐like receptor 9 (TLR9) recognizes both bacterial and self‐DNA and it is abundantly expressed in the gastrointestinal tract. In this study, we investigated the influences of both bacterial DNA and specific short DNA sequences on TLR9‐mediated gastrointestinal cancer cell invasion. We assessed the effect of various DNA ligands on cellular invasion and on TLR9 and matrix metalloproteinase expression of three gastrointestinal cancer cell lines. DNA‐ligands described in this study include CpG‐ODN M362, 9‐mer (hairpin), human telomeric sequence h‐Tel22 G‐quadruplex, and bacterial DNAs from Escherichia coli and Helicobacter pylori. All of the DNAs studied were demonstrated to induce invasion in the studied cells. The DNA‐induced invasion was inhibited with a broad‐spectrum MMP inhibitor and partly also with chloroquine suggesting that it could be mediated via MMP activation, endosomal signaling, and TLR9. Interestingly, H. pylori DNA was shown to induce a more pronounced invasion in a gastric cancer cell line than in the other cell lines. Our results suggest that bacterial DNA as well as deoxynucleotides having stable secondary structures (i.e. hairpins or G‐quadruplex structures) may serve as endogenous, invasion‐inducing TLR9‐ligands and promote local progression and metastasis of cancers in the alimentary tract. 相似文献
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Tian Zhang Lingyun Xia Zhejun Wang Robert E.W. Hancock Markus Haapasalo 《Journal of endodontics》2021,47(3):466-471
IntroductionThis study aimed to examine the dynamic recovery of established multispecies biofilms of oral bacteria after an initial treatment by D-enantiomeric peptide DJK-5, L-enantiomeric peptide 1018, or chlorhexidine digluconate (CHX).MethodsOral biofilms from 2 donors were grown on collagen-coated hydroxyapatite disks for 3 weeks and exposed to DJK-5, 1018, and 2% CHX for 3 minutes. Immediately after treatment and 1, 2, 3, 5, 7, 8, and 12 weeks after exposure, the biofilm volume and the volume ratio of dead and live bacteria in biofilms were assessed by confocal laser scanning microscopy using a live/dead viability stain. Results were examined by 1-way analysis of variance and post hoc multiple comparisons to determine significance at a P < .05 significance level.ResultsDJK-5 killed almost 80% of biofilms in 3 minutes and maintained this high level of dead bacteria for 1 week. The proportion of viable bacteria in DJK-5–treated biofilms returned to the pretreatment level after 12 weeks. The biovolume of DJK-5–treated biofilm remained significantly lower than that of biofilms after CHX and no treatment throughout the 12-week follow-up period (P < .001). The proportion of dead bacteria was higher in biofilms exposed to DJK-5 than with 1018 or CHX for 8 weeks after the exposure (P < .001). The proportion of dead bacteria almost doubled to 46%–52% during the first 7 days after the 3-minute exposure to CHX and peptide 1018. The timeline of biofilm recovery was slow but similar after exposure to CHX and the 2 peptides.Conclusionsecovery time after exposure to DJK-5 was longer than that after exposure to 1018 and CHX. Peptide 1018 showed a delayed, continued antibacterial effect similar to that of 2% CHX against the biofilm microbes. 相似文献
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8.
Eetu Niinimaki Petteri Muola Seppo Parkkila Ivana Kholová Hannu Haapasalo Silvia Pastorekova 《Scandinavian cardiovascular journal : SCJ》2016,50(3):162-166
Objectives. Carbonic anhydrase IX (CA IX) expression is induced by local hypoxia. We studied whether CA IX deposits associate with ascending aortic dilatation. Design. Aortic wall histology, CA IX expression, presence of leukocytes, plasma cells, macrophages, endothelial cells, smooth muscle cells, cell proliferation, elastin and collagen were studied in histological specimens collected from 30 patients who underwent surgery for ascending aorta. The samples were grouped according to presence of CA IX deposits. Results. Twenty out of 30 patients had CA IX-positive deposits within the adventitia, whereas 10 specimens remained negative. Adventitial inflammation was increased in CA IX-positive samples as compared with CA IX-negative ones (p?<?0.01). The mean diameter of the ascending aorta at the sinotubular junction increased significantly in patients with CA IX-positive staining as compared with CA IX-negative cases (63?±?3 vs 53?±?2?mm, p?<?0.02). Receiver operating characteristic curve analysis confirmed the association of CA IX positivity with increased ascending aortic dilatation (AUC 0.766; S.E. 0.090; p?=?0.020; 95% C.I. 0.590–0.941). Conclusions. Positive CA IX staining in certain aortic specimens suggests that increased CA activity may contribute to ascending aortic dilatation. 相似文献
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Sami Salo Ville Leinonen Toni Rikkonen Pauli Vainio Jarkko Marttila Risto Honkanen Marjo Tuppurainen Heikki Kröger Joonas Sirola 《Maturitas》2014