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71.
The contents of 10 minor and trace elements in histologically confirmed gastric adenocarcinomas and their corresponding normal gastric mucosal tissues obtained from 39 patients at the time of gastric resection were simultaneously determined by instrumental neutron activation analysis. Specimens were irradiated by reactor neutrons and subsequently subject to direct analysis using a high-resolution HPGe -spectrometer. Univariate analysis revealed that gastric cancer tissues had significantly higher concentrations of Fe, K, Mg, Na, Rb, Se, and Zn than normal gastric mucosal tissues. However, multivariate analysis found that Fe, K, and Se were independent elements that associated with gastric cancer. Upon further evaluation of their clinical significance, we found a high tissue K level was related to lymphatic duct metastasis. High Se tissue levels were linked to intestinal type adenocarcinoma. A positive correlation was found between high Fe levels and vascular involvement. These findings suggest that Fe and K are associated with gastric cancer progression. Se is involved in carcinogenesis of stomach in high-risk areas. The mechanisms that underlie the corresponding pathohistological features deserve further study.  相似文献   
72.
73.
Stenosis phantoms were created to study the ability of "black blood" methods to image a vessel stenosis in the presence of pulsatile flow. Black blood images were acquired with a modified TurboFLASH (fast low-angle shot) method that eliminates flow signal by applying a set of prepulses before segmented data acquisition. With this high-speed approach, imaging can be completed within 16 seconds. This technique was compared with conventional spin-echo black blood, gradient-echo black blood, and gradient-echo bright blood methods. Loss of flow signal, which extended beyond the site of the stenosis, was seen on the gradient-echo bright blood images. The pattern of signal loss varied with the type of stenosis. Flow voids were achieved with spin-echo black blood imaging; however, substantial ghosting artifacts were seen. With gradient-echo black blood imaging, it was difficult to eliminate all flow signal, particularly for in-plane flow. The modified TurboFLASH method produced high-quality black blood images in a fraction of the time needed for spin-echo imaging. It showed no ghosting artifacts even in the presence of pulsatile flow.  相似文献   
74.
The role of epidermal growth factor receptors (EGF-R) in osteogenic cell differentiation was investigated using preosteoblastic MC3T3-E1 (MC3T3) cells and osteoblast-like ROS 17/2.8 (ROS) cells. When cultured in the presence of β-glycerophosphate (GP) and ascorbic acid (AA), MC3T3 cells underwent spontaneous differentiation into osteoblasts which was confirmed as they expressed osteoblast markers such as alkaline phosphatase (ALP), bone sialoprotein (BSP) and osteocalcin (OC). Interestingly, the number of EGF-binding sites decreased during their differentiation into osteoblasts, and the osteogenic protein-1 (OP-1) treatment, which accelerated their differentiation, lowered the number of EGF-binding sites even further. On the other hand, ROS cells with high expression levels of osteoblast markers and no EGF-R, after being transfected with human EGF-R cDNA (EROS cells), expressed numerous EGF-binding sites as well as EGF-R mRNA and protein; in the process, they ceased to express osteoblast markers, indicating their dedifferentiation into osteoprogenitor cells. Both MC3T3 and EROS cells showed increased cell growth in response to EGF, whereas ROS cells did not. These results imply that the EGF/EGF-R system in osteogenic cells has a crucial function in osteoblast phenotype suppression and osteogenic cell proliferation.  相似文献   
75.
OBJECTIVE: To assess the contribution of the carbohydrate antigens, sialyl-Lewis X (sLe(x)) and sialyl-Lewis A (sLe(a)), which are known to be ligands for E-selectin, to the adhesion between human urothelial cancer cells and cytokine-activated human endothelial cells. MATERIALS AND METHODS: We studied the expression of sLe(x) and sLe(a) antigens of three bladder cancer cell lines (JTC 30, JTC 32, and T24) by flow cytometry and the adherence to interleukin 1beta-activated human umbilical vein endothelial cells (HUVEC). RESULTS: JTC 30 and JTC 32 cells expressed both sLe(x) and sLe(a) antigens, and showed adhesion to activated HUVEC, which was completely abolished by anti-E-selectin antibody. T24 cells expressed neither sLe(x) nor sLe(a) antigen, and did not adhere to activated HUVEC. Each of anti-sLe(a) or anti-sLe(x) antibody partially blocked the attachment of JTC 30 cells to activated HUVEC, and combination of these antibodies almost completely blocked the adhesion. The combination of antibodies did not significantly influence the adhesion of JTC 32 cells. CONCLUSION: These results indicate that both sLe(a) and sLe(x) carbohydrate antigens are involved in E-selectin-mediated adhesion of some urothelial cancers, and that there might be unknown ligands for E-selectin on urothelial cancer cells.  相似文献   
76.
Transforming growth factor-α (TGF-α) is a potent mitogenic polypeptide. It is secreted by a variety of transformed cells and tumors, modifying tumor growth through autocrine or paracrine mechanism. In the present study, serum levels of TGF-α were determined by enzyme-linked immunosorbent assay (ELISA) in 27 normal females, 116 patients with benign ovarian tumors, and 42 patients with epithelial ovarian cancers (10 with stage I, 7 with stage II, 19 with stage III, and 6 with stage IV). The ELISA assay could detect a minimum level of serum TGF-α concentration at 10 pg/ml. Serum samples were obtained from normal females and from patients with benign or malignant ovarian tumors before initial surgery. The detectable rates were 11% (3/27) in normal females, 28% (32/116) in benign ovarian tumors, and 62% (26/42) in ovarian cancers. The detectable rates in serous and endometrioid ovarian cancers were 71 and 70%, respectively, which were higher than the rate of 33% in mucinous type. However, there was no obvious relationship between the detectability of serum TGF-α and the stages of ovarian cancers. The mean concentration of TGF-α in ovarian cancer was 159.8 pg/ml, which was significantly higher than 27.7 pg/ml in benign ovarian tumors (P< 0.001) as well as 15 pg/ml in normal females (P< 0.001). The mean concentrations of serum TGF-α in stages I to IV ovarian cancers were 133.5, 96.2, 194.8, and 178.3 pg/ml, respectively. The mean concentration of serum TGF-α in any two stages of ovarian cancers was not statistically different. In conclusion, measurement of serum TGF-α can be used as a supplementary tumor marker to differentiate a malignant ovarian tumor from a benign one. However, the concentration of serum TGF-α has no special relation with the stage of ovarian cancer itself. Because of the small number of stage I ovarian cancers with detectable TGF-α in the present investigation, it would probably not be feasible to differentiate a stage I ovarian cancer from a benign ovarian tumor based only on the level of TGF-α in serum.  相似文献   
77.
A 63-year-old men suffered from fever, jaundice, and right upper quadrant pain for 1 week. Biliary stones with biliary tract infection were diagnosed. He was treated with parenteral antibiotics. However, abdominal ultrasonography showed multiple hyperechoic lesions in both lobes, and infiltrating hepatocellular carcinoma was suspected initially. Numerous hypervascular nodular-enhancing lesions were revealed by computed tomography. Magnetic resonance imaging further disclosed numerous tiny cystic lesions with peripheral enhancement. Exploratory laparotomy was performed for biliary calculi and probable underlying malignancy. Cholecystectomy, choledocholithotomy, and liver wedge biopsy were done. The pathology revealed bile duct hamartomas with microabscess formation. The past literature about biliary hamartomas is reviewed.  相似文献   
78.
Objectives: The etiology of male breast cancer is obscure, although an excess risk has been associated with Klinefelter syndrome, testicular disorders, benign breast disease including gynecomastia, use of exogenous estrogens, radiation, and a family history of male or female breast cancer. We conducted a case-control study to investigate risk factors further for breast cancer in men.Methods: Based on data from the 1986 National (United States) Mortality Followback Survey (NMFS) of almost 20,000 deceased adults (age 25 years or over), we compared information obtained from next-of-kin interviews of 178 men who died of breast cancer with that of 512 male controls who died of other causes. Information was obtained on selected demographic and other factors, including diet, exercise, occupation, height and weight, and use of tobacco and alcohol.Results: Increased risks were found for men who were described by their next-of-kin as very overweight (odds ratio [OR] = 2.3, 95 percent confidence interval [CI] = 1.1-5.0). The risks associated with the three upper quartiles of body mass index (BMI) (wt/ht2) were 1.3, 1.6, and 2.3, respectively, with a significant dose-response relationship (P < 0.01). An excess risk was also associated with limited exercise (OR = 1.3, CI = 0.8-2.0). Consumption of red meat was associated with an increased risk, and consumption of fruits and vegetables with a decreased risk, although the trends were not significant. No association was found for tobacco or alcohol use, but an excess risk was associated with higher levels of socioeconomic status (SES) (OR = 1.8, CI = 1.1-3.0).Conclusions: Our study suggests that obesity increases the risk of male breast cancer, possibly through hormonal mechanisms, while dietary factors, physical activity, and SES indicators also deserve further investigation. Cancer Causes andd Control 1998, 269-275  相似文献   
79.
Thirty-four consecutive women undergoing endometrial laser ablation, as a treatment of menorrhagia, were recruited to assess the validity of fluid absorption monitoring by a new continuous automated system (AquaSens). The same group of women also had monitoring of fluid absorption carried out by our standard technique of weighing. The intra-class correlation coefficient for the fluid deficit estimated by AquaSens compared to our standard technique of manually weighing the irrigation bags was 0.98 (95% CI 0.96–0.99). Aquasens therefore provides a valid and non-invasive method of continuously monitoring fluid deficit amongst patients undergoing operative hysteroscopy procedures, thereby reducing the risk of unexpected fluid absorption and its potentially fatal sequelae.  相似文献   
80.
Microcystin-LR (MC-LR), a cyanobacterial toxin, is a potent inhibitor of protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A). PP1 and PP2A are critical regulators in embryonic development. However, the effects of MC-LR in embryonic development have been controversial. MC-LR has been demonstrated to be highly toxic in medaka, but not in zebrafish or rabbit embryos. The causes of difference may be due to membrane impermeability that impaired the delivery of MC-LR into cytoplasm of zebrafish and rabbit embryos. Therefore, we microinjected MC-LR directly into developing zebrafish embryos and investigated the effects of MC-LR on embryonic development. We demonstrated that MC-LR induced the lethality of zebrafish embryos in a dose- and time-dependent manner. MC-LR also induced the loss of blastomere coherence via the interference of beta-catenin and cadherins distributions. Furthermore, the MC-LR treated fry revealed various developmental defects. These results suggested that MC-LR might affect the phosphorylation equilibrium of signaling molecules, including beta-catenin and cadherins, required early in zebrafish embryonic development.  相似文献   
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