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Although proliferating cell nuclear antigen (PCNA) is known to be an indicator of malignant potential in tumors, the biological and clinicopathological significance of PCNA in tumor tissue is controversial. METHODS: Immunohistochemical expression of PCNA was examined in 58 gastric carcinoma tissues obtained at autopsy to test the clinicopathological significance. In addition, in 24 of the 58 tumor tissues we compared immunohistochemical expression of PCNA in biopsy and autopsy specimens from the same patient in order to know whether the proliferating activity of tumor cells is stationary from the early stage to the end of tumor growth. RESULTS: 1. PCNA was undetectable in some tumor tissues (12.5% in biopsy and 10.3% in autopsy specimens). 2. the frequency of PCNA positive cases and labeling index (LI) (%) of PCNA in tumor tissues were not significantly different between biopsy and autopsy specimens. 3. the intensity of PCNA reaction was not related to prognosis. 4. PCNA positive cases and LI did not correlate with survival condition. CONCLUSION: It is hard to say whether PCNA is a reliable indicator in predicting malignancy and prognosis of gastric cancer.  相似文献   

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OBJECTIVES: A technique was developed for three-dimensional (3D) modeling of prostate cancer and transrectal biopsies. To test the model, the cancer yield of a simulated 10-biopsy protocol was compared with a simulated sextant protocol and with preoperative biopsies regarding cancer detection and correlation with tumor volume. METHODS: Transrectal ultrasound-guided core biopsies were taken from 81 men according to a standardized 10-biopsy protocol that included sextant biopsies. The patients underwent radical prostatectomy and specimens were step-sectioned and whole-mounted. Cancer and the prostate capsule were outlined on the slides and the regions transferred to a computer software program developed by our group. A 3D volume of each prostate was reconstructed from the sections. Virtual core biopsy needles imitating the positions of the real biopsies were inserted into the prostate and the cancer yield was calculated. Only the standardized positions were considered in this study (ie, additional biopsies from hypoechoic foci were not accounted for). RESULTS: Of the cancers detected with 10 standardized virtual biopsies, 24% would have remained undetected with sextant biopsies. The cancer yield of 10 virtual biopsies correlated with the preoperative biopsies (r = 0.64) and with the tumor volume (r = 0.56). A multiple regression analysis showed that the cancer yield of a simulation of 10 biopsies correlated better with tumor volume than did a simulation of sextant biopsies (P = 0.02). CONCLUSIONS: We conclude that computer-assisted 3D reconstruction of prostate cancer can be used as a model for evaluation and optimization of biopsy protocols.  相似文献   

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BACKGROUND: Proliferative activities of tumors are thought to be prognostic features of malignant tumors, but their value as measured by proliferating cell nuclear antigen (PCNA) labeling remains unclear in gastric cancer. METHODS: PCNA labeling rates (LR) were quantified in 121 paraffin-embedded biopsy specimens from primary tumors by immunocytochemistry. RESULTS: Immunohistochemical analyses have demonstrated that PCNA presents an intense staining in the nuclei of tumor cells and mucous neck cells of gastric glands. The PCNA LR ranged from 12% to 79% (mean +/- standard deviation), and a significant correlation was found between bromodeoxyuridine labeling indices and PCNA LR: PCNA LR were closely associated with tumor size, serosal invasion, and nodal involvement. The patients with tumors with high PCNA LR (greater than 40%) were dead significantly earlier than were those with tumors with low PCNA LR: When the PCNA LR and all the clinicopathologic parameters were entered into a Cox regression model, PCNA LR emerged as an independent prognostic factor. CONCLUSION: These results indicate that PCNA LR may be a potentially useful prognostic factor for gastric cancer.  相似文献   

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The primary objective of this investigation was to study the effect of D-alpha-tocopherol acid succinate (vitamin E succinate) and prostaglandin E2 (PGE2), individually and in combination, on the proliferation of human tongue squamous carcinoma cells (SCC-25) in vitro. Test compounds in varying concentrations were incubated with cells in serum-free Dulbecco's Modified Eagle's Medium-Ham's F-12 Medium (50:50), supplemented with 0.1% albumin for sixteen hours. Cell proliferation was measured by the incorporation of [3H] thymidine in acid-insoluble material (i.e. DNA). Prostaglandin E2 and vitamin E succinate, individually at 10(-9)-10(-6) M, caused significant dose-dependent inhibition in DNA synthesis. A combined dose of each compound at 10(-5) M resulted in significant additive inhibition which averaged 43.53% (p < 0.005). Addition of indomethacin (INDO) to cell cultures induced significant dose-dependent stimulation in DNA synthesis. Hence, we might suggest that the overall potential of vitamin E in controlling malignant cell proliferation in vivo could be due to its own effect combined with that of endogenous PGs which are normally produced in excessive amounts by malignant cells.  相似文献   

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BACKGROUND: Eukaryotic initiation factor 4E (eIF-4E) is a 25-kilodalton phosphoprotein that binds specifically to mRNA as the initial step for mRNA translation. An elevated level of eIF4E has been associated with the up-regulation of various protooncogene products. Transfection of cell lines by viral vectors with eIF4E overexpression has resulted in malignant transformation. The objective in this study was twofold: to examine benign and malignant breast specimens for eIF4E expression, and to determine whether eIF4E overexpression may have prognostic potential. METHODS: Western blot analysis was performed on benign and malignant breast specimens using anti-eIF4E rabbit antiserum. Quantification was accomplished by developing blots with nitroblue tetrazolium and 5-bromo-4-chloro-3-indolyl phosphate and densitometry. Confirmation of eIF4E overexpression at the cellular level was performed using immunohistologic staining in situ. RESULTS: The authors examined 112 breast specimens for eIF4E protein expression. Of the 52 benign breast specimens examined, none showed eIF4E overexpression. All 12 ductal carcinoma in situ specimens were found to overexpress eIF4E in the intermediate range (mean elevation: 2.5-fold). Of the 48 breast carcinoma specimens examined, all had eIF4E elevation at levels of 3-30-fold (mean: 10.5 +/- 0.9-fold). Charts from 39 patients with Stage I, II, and III breast carcinoma were reviewed. In ten patients with eIF4E overexpression of < sevenfold, there was no recurrence or death from breast carcinoma. In the 29 breast carcinoma patients with > or = 7-fold eIF4E overexpression, 9 patients had breast carcinoma recurrences and 5 had died from disease at last follow-up. The median follow-up in this study was 34.5 months. CONCLUSIONS: Overexpression of eIF4E was observed in malignant breast specimens but not in normal or benign breast tissues. In patients with breast carcinoma, the group with high eIF4E overexpression (> or = 7-fold) experienced a worse clinical outcome (higher recurrences and death) compared with the group with low eIF4E overexpression (< 7-fold).  相似文献   

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CT scans of eight nonsmoking patients with chronic sinusitis and two controls were graded for their disease severity (from 0 to IV) with the classification system proposed by May. Subsequently, endoscopically harvested middle turbinate specimens from these patients (16 diseased turbinates, 4 controls) were evaluated both by scanning and by transmission electron microscopy. As the severity of the disease increased as demonstrated by CT scan, electron microscopy of 5 x 3 x 0.05 mm mucosal specimens demonstrated that the number of ciliated cells decreased whereas the number of goblet and squamous cells increased. As the disease progressed to stages III and IV, scanning and transmission electron microscopy demonstrated areas of squamous metaplasia and areas completely denuded of epithelium. The increased goblet cell population, the loss of cilia and ciliated cells, and the patches of denuded epithelium may account for the recurrent bacterial infections and chronic nasal drainage seen in patients with chronic sinusitis. The extensive mucosal changes that occur in grade III and IV disease are similar to those occurring in cigarette smokers, and it takes years to recover after discontinuation of smoking. Delayed recovery of the mucosal epithelium may account for both the recurrent infections and the slower response to treatment on the part of patients with extensive grade III and IV changes on the CT scan.  相似文献   

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The bark of the yohimbine tree has long been appreciated as an aphrodisiac. Recent studies have shown that yohimbine is effective in the symptomatic treatment of erectile dysfunction. It is superior to placebo and has fewer side effects compared with the invasive treatment of erectile dysfunction. The evidence for effectiveness seems less compelling for other oral drugs used in this condition. It can be concluded that yohimbine is an attractive option in the symptomatic treatment of erectile dysfunction.  相似文献   

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The feasibility of screening for the antibody to HCV by pooling 10 serum specimens was studied by utilizing the epidemiologic method of single blind random allocation. We changed only the ratio between the pooled serum specimen volume and the serum specimen diluent volume, with their total volume and single serum specimen volume being as much as the volume required by EIA. Other steps were the same as those of EIA. The result showed that taking single serum specimen as the control group, the sensitivity and specificity of pooled serum specimen were 100% and 97.6%, respectively. The false positive rate was 2.4%, Kappa value was 0.95 (P < 0.05). The analysis of profit found that remarkable social and economic benefit will be obtained when serum pooling method is used. These results demonstrate that pooling 10 serum specimens is feasible to screening the antibody to HCV in blood donors by EIA.  相似文献   

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We characterized a murine monoclonal antibody, PT25-2 (IgG1), raised against washed human platelets. The antibody and its Fab fragments were both capable of inducing platelet aggregation in a fibrinogen-dependent manner and induced 125I-fibrinogen binding to unstimulated platelets (120,000 molecules/platelet at a 100 nM IgG concentration). The antibody immunoprecipitated the alpha IIb beta 3 complex from lysates of iodinated platelets but did not react with the respective subunits when complex formation was disrupted by treatment with 5 mM EDTA at 37 degrees C for 30 min. However, simply removing the extracellular divalent cation with EDTA had no effect on antibody binding indicating that the antibody's epitope depends upon a conformational structure maintained by alpha beta subunit association. Antibody binding to unstimulated, washed platelets yielded binding parameters (Kd = 40 nM, Bmax = 100,000 molecules/platelet), which were found to be virtually unchanged when binding was performed using thrombin or RGDS-peptide-stimulated platelets. Thus, the PT25-2 antibody defines a novel regulatory epitope expressed by the alpha IIb beta 3 integrin on unstimulated, quiescent platelets.  相似文献   

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The object of this study is to establish anti-idiotype (anti-ID) monoclonal antibodies (MoAbs) against a human MoAb (4G12) that highly reacts with lung squamous cell carcinomas. Two murine anti-ID MoAbs (2H1 and 2B12) were established by hybridoma technology. They showed specific reactivity with 4G12 but not with 3H12 human MoAb, human IgM and human IgG. These two MoAbs demonstrated more than 90% of binding inhibition of 4G12 to lung squamous cell cancer cell line (PC10). Moreover, cross inhibition test showed that 2H1 and 2B12 detect different idiotypes of 4G12 each other. Furthermore, specific reactivity of anti 2H1 and anti 2B12 sera to PC10 were observed by cell binding ELISA. These two anti-ID MoAbs had internal image of the original antigen.  相似文献   

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本文利用水热法合成了六角形磁铅石结构的BaNdxFe(12-x)O(19)铁氧体,用X射线衍射仪、透射电子显微镜和振动样品磁强计等仪器对粉末的结构、形貌和磁学性能进行了研究,并讨论了Nd(3+)对钡铁氧体磁学性能的影响。结果表明,Nd(3+)可以明显提高BaFe(12)O(19)粉末的矫顽力。  相似文献   

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铸造法制备Al63Cu25Fe12准晶   总被引:1,自引:0,他引:1  
通过常规铸造法制备了Al63Cu25Fe12准晶合金,并对其热处理工艺进行了初步探索,采用显微镜和扫描电镜观察了金相组织,采用XRD衍射分析了其中的准晶相及类似晶体相。研究结果表明,铸造法制备的AlCuFe准晶材料中主要由二十面体I相、立方结构β相和单斜结构入相3种物相组成。常熔铸制备的Al63Cu25Fe12准晶合金在接近I相熔点长时间退火,可以显著提高I相的含量。  相似文献   

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针对EAF-LF(VD)-VC工艺生产的大型船用S34MnV曲拐探伤不合的问题,分别在电炉还原期、LF-VD精炼期、浇注和锻造后钢锭取样对钢中夹杂物进行了研究.结果表明,精炼期间大于15μm的夹杂物比例波动在1.65%~10.34%之间;钢锭横截面上凝固前沿的柱状晶截获夹杂物的几率不同,帽口中心部位大型夹杂物含量少于边部试样夹杂物含量为5.81mg/10kg;钢锭尾部中心部位夹杂物含量高于边部试样夹杂物含量为25.9mg/10kg;锻造钢锭中夹杂物富集严重,其中尾部DS类夹杂达到了4级以上.钢锭锻造后尾部含有大型夹杂物聚集部分不能完全切除是目前导致产品探伤不合的一个主要原因.  相似文献   

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