Cadmium, arsenic, selenium and iron- Implications for tumor progression in breast cancer.

The aim of this study was to determine Cd (cadmium) and As (arsenic) contents in human breast cancer tissues, investigate their interactions with Se (selenium) and Fe (iron), and assess their further implications for tumor progression. Metal contents were determined in 42 tissue sets (tumor and adjacent tissue) collected from 42 women diagnosed with primary breast cancer. Analytical methods included AAS and ICP-MS techniques. Significantly higher contents of Cd (p=0.0003), Se (p<0.0001) and Fe (p=0.0441) whereas significantly lower content of As (p<0.0001) were observed in tumors as compared to adjacent tissues. There was a significant positive correlation between Cd and As contents in tumor tissue. However, only Cd was significantly associated with histological type of tumor, its size, grading and progesterone receptor status. This study support the role of Cd in breast cancer risk and progression. The possible link between As exposure and breast cancer is still not clear.

DNA damage and oxidative stress response to selenium yeast in the non-smoking individuals: a short-term supplementation trial with respect to GPX1 and SEPP1 polymorphism.

PURPOSE: Selenium, both essential and toxic element, is considered to protect against cancer, though human supplementation trials have generated many inconsistent data. Genetic background may partially explain a great variability of the studies related to selenium and human health. The aim of this study was to assess whether functional polymorphisms within two selenoprotein-encoding genes modify the response to selenium at the level of oxidative stress, DNA damage, and mRNA expression, especially in the individuals with a relatively low selenium status. METHODS: The trial involved 95 non-smoking individuals, stratified according to GPX1 rs1050450 and SEPP1 rs3877899 genotypes, and supplemented with selenium yeast (200 µg) for 6 weeks. Blood was collected at four time points, including 4 weeks of washout. RESULTS: After genotype stratification, the effect of GPX1 rs1050450 on lower GPx1 activity responsiveness was confirmed; however, in terms of DNA damage, we failed to indicate that individuals homozygous for variant allele may especially benefit from the increased selenium intake. Surprisingly, considering gene and time interaction, GPX1 polymorphism was observed to modify the level of DNA strand breaks during washout, showing a significant increase in GPX1 wild-type homozygotes. Regardless of the genotype, selenium supplementation was associated with a selectively suppressed selenoprotein mRNA expression and inconsistent changes in oxidative stress response, indicating for overlapped, antioxidant, and prooxidant effects. Intriguingly, DNA damage was not influenced by supplementation, but it was significantly increased during washout. CONCLUSIONS: These results point to an unclear relationship between selenium, genotype, and DNA damage.

Diet and the content of selenium and lead in patients with abdominal aortic aneurysm.

BACKGROUND: To evaluate the content of selenium (Se) and lead (Pb) and the influence of dietary habits and smoking in patients with abdominal aortic aneurysm (AAA). PATIENTS AND METHODS: Forty-nine patients with AAA prior to surgical procedures aged 42 - 81 years and a control group of 22 healthy volunteers aged 31 - 72 years and 17 aortic wall samples from deceased were included in the study. Food-frequency questionnaires were implemented in AAA patients to collect the dietary data. Se and Pb concentrations in the serum and blood, respectively, and in arterial wall and parietal thrombus samples were determined by the atomic absorption spectrometry method. RESULTS: The mean Se level in serum of patients with AAA (60.37 ± 21.2 cm/L) was significantly (p < 0.008) lower than in healthy volunteers (75.87 ± 22.4 cm/L). We observed a significant correlation (r = 0.69, p < 0.0001) between the content of Se in serum and the parietal thrombus of examined patients. Se concentration in aortic wall was inversely correlated to the concentration of Pb (r = - 0.38, p < 0.02). We observed significantly lower (p < 0.05) concentrations of Se (39.14 ± 37.1 cm/g) and significantly higher (p < 0.05) concentrations of Pb (202.69 ± 180.6 cm/g) in aortic wall samples of smoking patients than in non-smoking patients (77.56 ± 70.0 cm/g, 73.09 ± 49.8 cm/g; respectively). CONCLUSIONS: Se serum level is lower in patients with AAA than in healthy volunteers. In aortic wall, Se concentration is inversely correlated with Pb concentration. Dietary habits and smoking have an influence on the Se and Pb status in patients with AAA.

Optimization of an algorithm for measurements of velocity vector components using a three-wire sensor.

Hot-wire measurements of velocity vector components use a sensor with three orthogonal wires, taking advantage of an anisotropic effect of wire sensitivity. The sensor is connected to a three-channel anemometric circuit and a data acquisition and processing system. Velocity vector components are obtained from measurement signals, using a modified algorithm for measuring velocity vector components enabling the minimization of measurement errors described in this paper. The standard deviation of the relative error was significantly reduced in comparison with the classical algorithm.

Proliferation of transplanted allogeneic pancreatic islets.

Recent studies showed enhanced regeneration of pancreatic islets in some circumstances. The purpose of our study was to investigate the proliferate potential of rat pancreatic islet cells in allogeneic grafts. Adult Lewis female rats and WAG male rats served as recipients and donors, respectively. Diabetes was induced by single intravenous (IV) injection of streptozotocin producing diabetes as confirmed by nonfasting plasma glucose >300 mg% on 3 consecutive days. Islet rejection was considered complete when glycemia exceeded 250 mg% and was confirmed by histopathological examination. To obtain long survival of allogeneic islets a tolerance-inducing method used allogeneic UV-B irradiated bone marrow transplantation into nonlethally selectively cytoreducted recipients with a donor-type splenocyte infusion followed by cyclophosphamide 200 mg/kg bw. Endocrine cell proliferation was assessed morphometrically using double immunostaining for pKi-67 and insulin or glucagon. Double immunolabelling, propidium iodide staining, and TUNEL assay were used to identify both proliferating and apoptotic cells. The rise of glycemia >350 mg/dL after graftectomy in euglycemic recipients was correlated with immunohistological examination, showing that the euglycemia was due to properly functioning pancreatic islet allotransplants. The immunohistochemical examination confirmed the presence of endocrine beta and alpha cells. In comparison with normal pancreas which showed 0.4 +/- 0.12%, pKi-67-positive cells, long-surviving grafts had a significantly higher proliferation capacity (5.61 +/- 0.94%; P <.001). In contrast, rejected grafts/control groups did not show significantly enhanced proliferation (0.73 +/- 0.19%), and had endocrine cells undergoing apoptosis. The incidence of apoptosis in endocrine cells within long-surviving graft appeared to be extremely low. In conclusion, the growth and death of endocrine cells in allogeneic grafts differ between accepted and rejected cases. The level of proliferation in the graft at day 150 was significantly higher compared with normal pancreatic beta cells.

Protoporphyrin derivatives--the use in localization of neoplasmas by titanium laser-induced fluorescence technique.

Examples of in vivo detection of skin neoplasmas (Mercl, melanoma) and breast carcinoma using laser induced fluorescence (LIF) and bis-1[1-alanylo-N]-ethylodeuteroporphyrin (Ala-PP) are described in this study. Photosensitizer, wave titanium laser and standard CCD camera coupled to vision amplifier enable precise neoplasm imaging, Ala-PP retention monitoring and further photodynamic therapy (PDT).

Beneficial effect of proteases on allograft arteriosclerosis in a rat aortic model.

Recently it has been shown that protease therapy ameliorates certain immune-mediated diseases. Thus we studied the effect of administration of a protease mixture on aortic transplant arteriosclerosis in rats. Segments of abdominal aorta from SHR strain were transplanted orthotopically into WKY recipients. Two groups of allografted rats were used. One group (n = 8) was treated with daily intraperitoneal injections of 12 mg of a protease formulation containing trypsin, bromelain and rutosid, and another group (n = 8) with placebo. Eight WKY rats were transplanted with syngenic aortas and treated with placebo. After 8 weeks, structural changes of the grafted segment were evaluated by morphometric analysis of formalin-fixed sections with specific stains. In untreated allografts there was a marked intimal thickening, medial necrosis with disruption of elastic fibres, and inflammatory infiltrates in the adventitia. Administration of proteases inhibited formation of neointima by 59.0% when cross-sectional areas were compared (80+/-11 versus 195+/-11 microm2, P<0.01; protease-versus placebo-treated allograft recipients respectively) and decreased medial injury as estimated by the integrity of elastic fibres and smooth-muscle cell density. Thus, in an experimental model of rat aortic allograft, protease administration ameliorates rejection-induced arterial wall remodelling.