Blood-group phenotypes, sulfomucins, and Helicobacter pylori in Barrett's esophagus

Barrett's esophagus, morphologically analogous to gastric intestinal metaplasia, often precedes the development of esophageal adenocarcinoma. In the stomach, expression of sulfomucins and aberrant Lewis(a) (Le[a]) antigen is an excellent predictor of premalignant progression, and Helicobacter pylori infection is a crucial determinant for the development of atrophy, metaplasia, and adenocarcinoma. In the esophagus, the significance of sulfomucin expression is controversial, the aberrant expression of Le(a) has not been explored, and the role of H pylori in the evolution of preneoplastic conditions is unknown. We investigated in 155 patients referred for endoscopy the association of Barrett's esophagus with expression of sulfomucins, Lewis, secretor, and ABO phenotypes, and H pylori infection. We report a subtype of intestinal metaplasia, present in all patients with esophageal adenocarcinoma, similar to gastric intestinal metaplasia of colonic type (type III or incomplete), that expresses sulfomucins and aberrant Le(a) in goblet and columnar cells. Lewis(a+b-), nonsecretor and blood group A phenotypes, were all positively associated with esophageal adenocarcinoma, suggesting a genetic susceptibility. H pylori infection was detected in 75% of patients with esophageal adenocarcinoma.     

The home treatment of deep venous thromboses with low-molecular-weight heparin

Low-molecular-weight heparins (LMWH) have shown to be at least as safe and efficient as non-fractionated heparin in the treatment of deep-vein thrombosis (DVT). Moreover, no serial laboratory controls are required. Therefore, LMWH allow the patients to be treated at home. From July 1995 to July 1996, 30 consecutive patients with DVT were enrolled in a prospective study and treated with nadroparin. Ambulatory treatment was feasible in 24 patients (9 patients did not require admission and 15 patients were discharged in less than 6 days). The main causes for admission were the inability to obtain a diagnosis, the severity of symptoms in the involved limb, and the presence of associated disease. None of the 24 patients to whom the possibility of home therapy was offered desired to remain at hospital. The ambulatory care of these patients increased the burden on primary care teams. There was no case of clinical recurrent thromboembolism nor a major hemorrhagic complication. Ambulatory treatment of DVT with nadroparin seems to be feasible, efficient and safe. Nevertheless, before using this therapeutic alternative a series of factors should be considered, which include the severity of clinical presentation, the embolic and hemorrhagic risks, and the presence of associated diseases.     

Investigation of the structural stability of Co2NiGa shape memory alloys via ab initio methods

CoNiGa alloys have received considerable interest due to their high-temperature shape memory properties. Although there have been many investigations on the mechanical and magnetic behavior of these materials, little is known about the microscopic basis for the observed macroscopic behavior. In this work, we discuss the stability of Co₂NiGa-based structures. The austenite phase is modeled as fully ordered L2₁ and as partially ordered B2. The stability of the austenite phase with respect to tetragonal distortions is examined. Lattice dynamics calculations suggest that the mechanism for the transformation is different from that of the much more studied and chemically similar Ni₂MnGa shape memory alloy (SMA). The electronic basis for the observed metastability of the cubic Co₂NiGa austenite is found to be qualitatively different from that observed in other ferromagnetic SMAs, especially Ni₂MnGa.     

Efficient synthesis of PbTe nanoparticle networks

The synthesis of semiconductor nanocrystalline networks using weak capping ligands in aqueous media has been demonstrated. Carbohydrates, including ?-cyclodextrin, D-(+)-glucose, D-glucosamine, lactobionic acid, sucrose, and starch were chosen as weak ligands to facilitate the formation of PbTe nanoparticle networks. The nanoparticle size, ranging from 5 nm to 30 nm, can be tuned by manipulating the temperature and concentration. Through a similar strategy, more complicated nanostructures including carbohydrate spheres@PbTe core-shell structures and Te@carbohydrate@PbTe multilayered submicron cables have been fabricated. This is a general approach which can be easily extended to the fabrication of other semiconductor networks, including PbSe and Bi₂Te₃ using carbohydrates and ethylenediaminetetraacetic acid (EDTA), respectively, as ligands.     

Efficient authentication and key distribution in wireless IP networks

Emerging broadband access technologies such as 802.11 are enabling the introduction of wireless IP services to an increasing number of users. Market forecasts suggest that a new class of network providers, commonly referred to as wireless Internet service providers, will deploy public wireless networks based on these new technologies. In order to offer uninterrupted IP service combined with ubiquitous seamless mobility, these multiprovider networks need to be integrated with each other, as well as with wide-area wireless technologies such as third-generation cdma2000 and UMTS. Therefore, efficient authentication and dynamic key exchange protocols that support heterogeneous domains as well as networks with roaming agreements across trust boundaries are key to the success of wide-area wireless IP infrastructures. In this article we first describe a simple network model that accounts fro heterogeneity in network service providers, and put forward the requirements any authentication and key exchange protocol that operates in such a model should satisfy, in terms of network efficiency, security, and fraud prevention. We then introduce a new authentication and key exchange protocol, wireless shared key exchange (W-SKE). We characterize properties and limitations of the W-SKE against the requirements discussed earlier. Finally, we contrast W-SKE against other well-known and emerging approaches.     

Predicting changes in the color of powders: Does Melamed's model fit to real industrial powders?

In 1963, Melamed proposed a model that expressed reflectance of a powder described as a population of spherical particles of unique diameter as a function of size, shape, and optical characteristics of the powder. This article shows how this model has been adapted to fit to industrial powders. An example of use for industrial quartz is given. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 413–419, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20058     

Spontaneous peritonitis in a cirrhotic patient with a cat: Pasteurella multocida infection of the ascitic fluid

Spontaneous peritonitis due to Pasteurella multocida is exceptional. As far as we know only 11 other cases have been reported. We describe a 45 year old patient who presented with a spontaneous Pasteurella multocida peritonitis as the first complication of a previously undiagnosed cirrhosis. The patient used to play with his pet cat, not recalling having ever sustained any injury. Cultures of the cat's mouth grew the same strain of Pasteurella multocida than was found in the patient's ascitic fluid. The clinical findings of the previous cases, most of which were also related to non traumatic exposure to domestic animals, are here described. Pasteurella multocida in one potential agent in the cirrhotic patient presenting with spontaneous peritonitis, especially if in close contact with animals, cats being the most often carriers.     

Formation of polymer-polymer complexes and blends in the system poly(acrylic acid)-poly(vinyl methyl ether)

The formation of a 1:1 polymer-polymer complex from poly(acrylic acid) and poly(vinyl methyl ether) has been detected by viscosity measurements in aqueous solution, and the glass transition temperature of the isolated complex has been determined. Infrared spectroscopy indicates that specific hydrogen bonding occurs between the components of the complex. Miscible blends of the two polymers can also be formed (at all compositions) and, although hydrogen bonding occurs, the structures of the blends are likely to be dissimilar to that of the complex.     

Minimal Complete Primitives for Secure Multi-Party Computation

The study of minimal cryptographic primitives needed to implement secure computation among two or more players is a fundamental question in cryptography. The issue of complete primitives for the case of two players has been thoroughly studied. However, in the multi-party setting, when there are n > 2 players and t of them are corrupted, the question of what are the simplest complete primitives remained open for t n/3. (A primitive is called complete if any computation can be carried out by the players having access only to the primitive and local computation.) In this paper we consider this question, and introduce complete primitives of minimal cardinality for secure multi-party computation. The cardinality issue (number of players accessing the primitive) is essential in settings where primitives are implemented by some other means, and the simpler the primitive the easier it is to realize. We show that our primitives are complete and of minimal cardinality possible for most cases.