Segmentation and quantification of human vessels using a 3-D cylindrical intensity model.

We introduce a new approach for 3-D segmentation and quantification of vessels. The approach is based on a 3-D cylindrical parametric intensity model, which is directly fitted to the image intensities through an incremental process based on a Kalman filter. Segmentation results are the vessel centerline and shape, i.e., we estimate the local vessel radius, the 3-D position and 3-D orientation, the contrast, as well as the fitting error. We carried out an extensive validation using 3-D synthetic images and also compared the new approach with an approach based on a Gaussian model. In addition, the new model has been successfully applied to segment vessels from 3-D MRA and computed tomography angiography image data. In particular, we compared our approach with an approach based on the randomized Hough transform. Moreover, a validation of the segmentation results based on ground truth provided by a radiologist confirms the accuracy of the new approach. Our experiments show that the new model yields superior results in estimating the vessel radius compared to previous approaches based on a Gaussian model as well as the Hough transform.     

DFMO Improves Survival and Increases Immune Cell Infiltration in Association with MYC Downregulation in the Pancreatic Tumor Microenvironment

Pancreatic ductal adenocarcinoma (PDAC) has an extremely poor five-year survival rate of less than 10%. Immune suppression along with chemoresistance are obstacles for PDAC therapeutic treatment. Innate immune cells, such as tumor-associated macrophages, are recruited to the inflammatory environment of PDAC and adversely suppress cytotoxic T lymphocytes. KRAS and MYC are important oncogenes associated with immune suppression and pose a challenge to successful therapies. Here, we targeted KRAS, through inhibition of downstream c-RAF with GW5074, and MYC expression via difluoromethylornithine (DFMO). DFMO alone and with GW5074 reduced in vitro PDAC cell viability. Both DFMO and GW5074 showed efficacy in reducing in vivo PDAC growth in an immunocompromised model. Results in immunocompetent syngeneic tumor-bearing mice showed that DFMO and combination treatment markedly decreased tumor size, but only DFMO increased survival in mice. To further investigate, immunohistochemical staining showed DFMO diminished MYC expression and increased tumor infiltration of macrophages, CD86⁺ cells, CD4⁺ and CD8⁺ T lymphocytes. GW5074 was not as effective in modulating the tumor infiltration of total CD3⁺ lymphocytes or tumor progression and maintained MYC expression. Collectively, this study highlights that in contrast to GW5074, the inhibition of MYC through DFMO may be an effective treatment modality to modulate PDAC immunosuppression.     

Erosion–Oxidation Behavior of Chromized–Aluminized 9% Chromium Steel under Fluidized-Bed Conditions at Elevated Temperature

An investigation into the erosion–oxidation behavior of chromized–aluminized 9% chromium steel has been carried out in a fluidized-bed erosion–oxidation rig in air at temperatures of 550 °C to 700 °C for particle impact angles of 30° and 90°, at speeds of 7.0–9.2 m s⁻¹. After exposure for 200 h, the mean-thickness changes were determined, and the specimens were examined and analyzed by scanning electron microscopy and X-ray diffraction. The results show that the chromized–aluminized specimens experience only relatively small amounts of material loss for 30° particle impacts but greater amounts for 90° particle impacts; such angle dependence is typical of a brittle erosion process. Under both impact angles, the thickness losses increase with increase in speed, and also, in temperature up to 650 °C, but then decrease with further increase in temperature. This change in the behavior between 650 and 700 °C is due to an increase in ductility of the coating and a greater contribution from oxidation. The two coating layers (an outer Al₁₃Cr₂ and an inner α-chromium layer) show similar behavior, i.e., have lower material loss rates under 30° impacts than under 90° impacts. As the oxidation rate of the α-chromium layer is greater than that of the outer layer, the oxide scale plays a greater role in the erosion process for the former, particularly under 30° impacts. These observations are discussed in terms of the thickness changes and the morphologies of the damaged surfaces, with the emphasis being put on the relative roles of growth of the oxide scales and removal of such scales (and the underlying coating) by the impacting particles.     

Limitations of codon adaptation index and other coding DNA-based features for prediction of protein expression in Saccharomyces cerevisiae

The relationship between codon usage and protein/mRNA expression in S. cerevisiae has been extensively studied. Recently, protein expression data for the whole yeast genome was published. We investigate which properties of coding DNA sequences can be used to predict expression levels. The new algorithm by Carbone et al. for computing dominating codon bias in a genome is evaluated. It is concluded that it works at least as well as existing methods, and eliminates the need to arbitrarily choose a set of highly expressed genes. Also, the hypothesis that information on codon pair frequencies can be used to predict expression is investigated. Our conclusion is that codon pairs do not contribute more information than do single codon frequencies. Overall correlation between predicted and actual expression data using properties of coding DNA sequences is around 0.65. Hence, while being a useful source of information, the expression levels predicted by these methods should only be used as a rule of thumb.     

Mechanical properties of carbon-modified silicon oxide barrier films deposited by plasma enhanced chemical vapor deposition on polymer substrates

Cohesive and adhesive properties of silicon oxide barrier coatings deposited from an oxygen/hexamethyldisiloxane gas mixture by plasma enhanced chemical vapor deposition, with controlled incorporation of carbon on 12 μm thick polyethylene terephtalate films were investigated. The reactor was equipped with a 2.45 GHz slot antenna plasma source and a 13.56 MHz-biased substrate holder. The two plasma sources were operated separately or in a dual mode. It was found that no or negligible internal stresses were introduced in the silicon oxide coatings as long as the increase of energy experienced by the film was compensated by the densification of the oxide. For a range of process parameters and carbon content on the changes of the crack onset strain, adhesion, and cohesion were found to be similar. Generally a high crack onset strain or good adhesion and cohesion were measured for films with an increased carbon content, although this was obtained at the expense of the gas barrier performance. Promising approaches towards high-barrier thin films with good mechanical integrity are proposed, based on coatings with a gradient in the carbon content and in the mechanical properties, on nano-composite laminates, and on organo-silane treatments.     

Pancreatico-jejunal anastomosis with invagination on isolated loop after cephalic pancreatoduodenectomy

The most frequent and most dangerous complication of the duodenopancreatectomy is pancreatic fistula due to dehiscence of the pancreatic anastomosis. A technique that uses a separate Roux en Y loop for pancreatic anastomosis, to reduce the fatal risks of the pancreatic fistula, has been initially reported more than 50 years ago. With the development of the pancreaticogastrostomy, it seems interesting to present a procedure using an isolated loop for the pancreas; this technique is derived from those previously published, allowing a good intussuception of the pancreas in the intestinal loop. This method has been performed in 35 duodenopancreatectomy (malignant pancreatic disease: 32 patients, benign pancreatic disease: 3 patients). The mean age of the patients was 64 years (range 34-74). There were four operative deaths unrelated to the pancreaticojejunal anastomosis and two pancreatic fistulas with spontaneous healing. The pancreatico-jejunostomy using a separate Roux en Y loop represented in this short experience a safe procedure to prevent pancreatic fistula.     

Development of coatings for protection in specific high temperature environments

Metallic and intermetallic coatings are widely used in jet engines and land-based gas turbines for oxidation and corrosion protection in the hotter parts of the engines. However there is a significant number of industrial processes where the use of protective coatings at high temperatures could contribute to a significant extension of life-time or an increase in operation temperature and thus efficiency. Examples of such industries are incineration and gasification of waste, biomass and coal, chemical process industries and petrochemical plants where highly aggressive environments are encountered containing species of e.g. carbon, chlorine, sulphur, vanadium or alcalines. Since most of these process environments contain only very low oxygen partial pressures or exhibit high concentrations of extremely aggressive compounds, the conventional, uncoated materials come to their limits. In recent years in laboratory work a number of new types of coatings have been developed for high-temperature applications which include diffusion coatings, overlay coatings and nanotechnological approaches for sealing porosity. In the paper the background of this development and the thermodynamic fundamentals are discussed together with some more recent solutions based on synergistic effects of multi-element coatings. Some results of performance tests of these coatings in sulfidizing, carburizing, chloridizing and vanadate environments will be presented. At the end conclusions can be drawn on the suitability of the different types of coatings for their specific applications.     

Prospective study of bacteremia rate after elastic band ligation and sclerotherapy of esophageal varices in patients with hepatosplenic schistosomiasis

Bone scintigraphy was performed in a 69-year-old male patient with adult T-cell leukemia suffering from right lower limb pain. Numerous sites of increased uptake were seen in the skull, left clavicle, bilateral humeri, bilateral radii and right femur and tibia. Bone radiographs showed multiple osteolytic lesions, most of which corresponded to the abnormal deposits on the bone scans with 740 MBq of 99mTc-hydroxymethylene diphosphonate. This pattern is rarely reported, but bone involvement of adult T-cell leukemia is not uncommon. Bone involvement was remarkable on the appendicular skeleton when compared with common metastatic bone tumors. Bone scintigraphy may be useful in detecting bone involvement in adult T-cell leukemia.     

Pharmacokinetics of the transdermal reservoir membrane system delivering beta-estradiol: in vitro/in vivo-correlation

We report here the evaluation of the potential of a serologic test to determine the endemicity of onchocercal infection in hyper, meso, and hypoendemic communities by the detection of antibodies to a cocktail of recombinant antigens. Parasitologic parameters of infection prevalence and intensity were compared with serologic results. Infection prevalence by serology was consistently but not significantly higher than that defined by parasitology. Differences between the communities defined by microfilarial load (CMFL) and a measurement of Onchocerca volvulus-specific antibody levels (serologic index [SI]) were similar. When stratified by age, differences were more significant in the younger age groups. If a sentinel population of 5-15-year-old individuals was used to compare communities, all could be equally ranked by serologic and parasitologic parameters. The SI of the sentinel population gave a better distinction between each community than the SI of the whole and would be sufficiently sensitive to measure the changes in endemicity that would be required for onchocerciasis control programs.