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101.
Activities of enzymes of the purine metabolic pathway, adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), and 5'- nucleotidase (5'-N), were investigated in the lymphoblasts of a patient with B-cell acute lymphoblastic leukemia. These lymphoblasts exhibited increased ADA activity and diminished activities of both PNP and 5'N' as compared to normal lymphocytes as well as non-T, non-B leukemia cells. This enzymatic pattern is identical to that which has been described in T-cell leukemic lymphoblasts and differs from that which has been observed in the malignant cells of undifferentiated B-cell lymphomas. These data suggest that there is biochemical heterogeneity within the spectrum of B-cell malignancies. Furthermore, inhibitors of ADA may be of use in those B-cell lymphoid neoplasms that exhibit increased ADA activity. 相似文献
102.
Melanie Spitzwieser Elisabeth Holzweber Georg Pfeiler Stefan Hacker Margit Cichna-Markl 《Breast cancer research : BCR》2015,17(1)
Introduction
It has been shown in some articles that genetic and epigenetic abnormalities cannot only be found in tumor tissues but also in adjacent regions that appear histologically normal. This phenomenon is metaphorically called field cancerization or field defect. Field cancerization is regarded as clinically significant because it is assumed to be an important factor in local recurrence of cancer. As the field showing these molecular abnormalities may not be removed completely by surgery, these changes might lead to neoplasms and subsequent transformation to a tumor. We aimed to investigate the applicability of the methylation status of six tumor suppressor genes as biomarkers for detecting field cancerization in breast cancer.Methods
The promoter methylation status of CCND2, DAPK1, GSTP1, HIN-1, MGMT and RASSF1A was determined by methylation-sensitive high-resolution melting (MS-HRM) analysis. MS-HRM methods for CCND2, MGMT and RASSF1A were developed in-house, primer sequences for DAPK1, GSTP1 and HIN-1 have already been published. Biopsy samples were taken from tumor, tumor-adjacent and tumor-distant tissue from 17 breast cancer patients. Normal breast tissues of four healthy women served as controls.Results
All MS-HRM methods proved to be very sensitive. LODs were in the range from 0.1 to 1.5 %, LOQs ranged from 0.3 to 5.3 %. A total of 94 %, 82 % and 65 % of the tumors showed methylation of RASSF1A, HIN-1 and MGMT promoters, respectively. The methylation status of these promoters was significantly lower in tumor-distant tissues than in tumor tissues. Tumor-adjacent tissues showed higher methylation status of RASSF1A, HIN-1 and MGMT promoters than tumor-distant tissues, indicating field cancerization. The methylation status of the HIN-1 promoter in tumor-adjacent tissues was found to correlate strongly with that in the corresponding tumors (r = 0.785, p < 0.001), but not with that in the corresponding tumor-distant tissues (r = 0.312, p = 0.239).Conclusions
Among the gene promoters investigated, the methylation status of the HIN-1 promoter can be considered the best suitable biomarker for detecting field cancerization. Further investigation is needed to test whether it can be used for defining surgical margins in order to prevent future recurrence of breast cancer. 相似文献103.
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106.
HELEN HØGH PETERSEN XU CHEN ADRIAN PIETERSEN JESPER HASTRUP SVENDSEN STIG HAUNSØ 《Pacing and clinical electrophysiology : PACE》1998,21(1):322-326
This study was designed to investigate the effect of the convective cooling of the tip of the ablation electrode during temperature controlled radiofrequency ablation. In vivo two different application sites in the left ventricle of anaesthetised pigs were ablated and in vitro ablation was performed during two different flow-velocities in a tissue bath, while electrode contact pressure and position were unchanged. Target temperature was 80 °C. Obtained tip temperature, power consumption and lesion dimensions were measured. In vivo lesion volume, depth and width were found significantly larger for septal applications than apical applications (p<0.01) and more power was used (p<0.001). Obtained tip temperature was significantly lower in the septal applications (p<0.001). In vitro increased convective cooling by induction of flow yielded larger lesion volume, depth and width (p<0.01), and had higher power consumptions (p<0.01). Obtained tip temperature did not differ significantly. For the given chosen target temperature power consumption was positively related to lesion volume (r= 0.66 in vivo and 0.65 in vitro), whereas obtained tip temperature was not (r = - 0.49 in vivo and - 0.61 in vitro). We conclude that during temperature controlled radiofrequency ablation lesion size differs for septal and apical left ventricular applications. Differences in convective cooling might play an important role in this respect. This is supported by our in vitro experiments, where increased convective cooling by induction of a flow around the electrode tip increases lesion dimensions and power consumptions. Furthermore we conclude that for the given target temperature the power consumption is positively correlated with lesion volume (p<0.001), whereas the obtained tip temperature is not. 相似文献
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109.
Hemodynamic significance of the paraumbilical vein in portal hypertension: assessment with duplex US 总被引:3,自引:0,他引:3
Mostbeck GH; Wittich GR; Herold C; Vergesslich KA; Walter RM; Frotz S; Sommer G 《Radiology》1989,170(2):339-342
Hemodynamic evaluation of portal and umbilical venous flow with duplex ultrasound (US) was performed in 11 patients with cirrhosis of the liver and a large umbilical vein. Two of these patients had hepatofugal flow in the umbilical vein exceeding hepatopetal flow in the portal vein. These two patients had no evidence of esophageal varices and bleeding. The remaining nine patients had esophageal varices. In these patients, the hepatopetal flow in the portal vein exceeded the hepatofugal flow through the umbilical vein. The authors conclude that duplex US may help identify the massive hepatofugal flow through a large umbilical vein that may reduce the likelihood of esophageal varices and variceal bleeding. 相似文献
110.
目的为了进一步保证巨乳缩小术后乳头乳晕的血供和感觉,减少手术并发症。方法设计应用乳房下真皮单蒂瓣,并保留部分乳腺组织的垂直乳腺蒂,及切除的乳腺组织位于乳房下方两侧的巨乳缩小术,自1994年1月至1995年11月,为67例(132侧)巨乳患者在法国斯德拉斯堡欧洲美容整形诊所进行治疗。结果术后全部患者无乳头乳晕并发症,感觉正常。结论结合乳腺垂直蒂和乳房下真皮单蒂瓣的改良巨乳缩小术,不但可以确保乳头乳晕的血供,且可减少感觉损伤,降低手术并发症,及提供良好形态。 相似文献