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Mycobacterium kansasii extrapulmonary infections are infrequent in immunocompetent adults. Rifampin (RIF), clarithromycin (CLR), isoniazid (INH) and ethambutol (EMB) are included in all the standard regimens against M.kansasii. We report a case of a healthy 65-year-old male farmer who presented with isolated right supraclavicular lymphadenopathy. The lymph node FNA showed acid-fast-bacilli and granulomatous inflammation. Quantiferon TB Gold test, HIV serology, and functional immunological studies were all negative or normal. He was put on a standard 4 drugs anti-tuberculous regimen that was switched to RIF + CLR+ INH after the Microbiology lab demonstrated an EMB-resistant Mycobacterium kansasii isotype I strain. The patient was cured after 12 months of therapy. This is the 6th reported case of M. kansasii extrapulmonary lymphadenitis in an immunocompetent adult and the 2nd showing EMB resistance in the world literature. Antimycobacterial regimens against M. kansasii, classically resistant to pyrazinamide (PZA) might also exclude EMB due to its increasing resistance in Europe. A 612 months therapy with at least 2 effective antimycobacterial drugs including RIF + CLR might be enough to treat extrapulmonary M. kansasii infections in immunocompetents.

Market liberalization has been carried out by many developing countries in the hopes of stimulating trade, investment and technology transfer. In order to analyze the impacts of liberalization on a specific industry sector, this paper compares the experiences of Brazil and Mexico in liberalizing the computer industry in the 1990s. The authors conclude that liberalization leads to lower prices and more rapid diffusion of computer use throughout the economy, but at a cost to domestic computer firms who were harmed by foreign competition. Both countries saw an increase in computer production, but Mexico's production was mainly for export to the United States, while Brazil was producing for the domestic market. The differences between outcomes in the two countries have been determined more by environmental factors than by the nature and pace of liberalization. © 2001 Elsevier Science Ltd.

To the Editor: Mycobacterium tuberculosis is the main causative agent of tuberculosis in humans. However, little attention has been paid to its transmission from humans to animals. We report M. [...]

Herein we evaluate the influence of an electric field on the coupling of two delocalized electrons in the mixed-valence polyoxometalate (POM) [GeV14O40]8− (in short V14) by using both a t-J model Hamiltonian and DFT calculations. In absence of an electric field the compound is paramagnetic, because the two electrons are localized on different parts of the POM. When an electric field is applied, an abrupt change of the magnetic coupling between the two delocalized electrons can be induced. Indeed, the field forces the two electrons to localize on nearest-neighbors metal centers, leading to a very strong antiferromagnetic coupling. Both theoretical approaches have led to similar results, emphasizing that the sharp spin transition induced by the electric field in the V14 system is a robust phenomenon, intramolecular in nature, and barely influenced by small changes on the external structure. [ABSTRACT FROM AUTHOR]

E-commerce began in Mexico in the early 1990s and has already extended into the main sectors of the economy, generating from its inception high optimism in both business and government circles. A number of factors, though, have dragged the process, which include a high degree of "informality" of the Mexican economy, a skewed income distribution, a traditional shopping culture, an also skewed business size structure, and a low level in the companies' technological development and organization structures. Nonetheless, e-commerce has taken its hold in Mexico. A critical set of enabling factors have prevailed over inhibiting forces, which include the large presence of multinational corporations, the liberalization of the telecommunications industry, the improvement of the country's telecommunications infrastructure, the creation of a basic legal framework, and the emergence of both e-banking and e-government. All indicates that such overall balance will continue to hold in the foreseeable future, so that the development of e-commerce in Mexico stands as a lasting phenomenon that may eventually lead to the rise of an economy significantly based on the Internet and other digital technologies, not just to the formation of an isolated "e-sector". The GEC survey discussed in this paper revealed that as much as 74 per cent of the business establishments included in the study use the Internet by for commercial purposes. This figure is far larger than the ones estimated on the basis of e-commerce revenues for the country as a whole, and thus changes the usual perception that e-commerce in Mexico has grown only to a limited extent. Accordingly, business establishments operating in Mexico outperform those in other countries included in the GEC survey regarding key aspects such as the use of e-mail, the construction and management of websites, the deployment and operation of EDI networks, and the improvement in their competitiveness, efficiency, and productivity. In a fundamental finding of this study, finance was found to be the most advanced sector in e-commerce adoption and development in Mexico. Financial firms and banking institutions proved to be the most globalized companies, the ones that use most extensively the Internet and Internet-based technologies for commercial purposes, the most advanced in systems integration, and the ones that spend the highest proportions of their operating budget in information systems. Conversely, and contrary to expectations, manufacturing establishments turned out to be the least advanced sector regarding e-commerce adoption and development, with distribution companies lying in the middle. The influence of size does not follow a regular pattern across all the sectors and aspects of e-commerce diffusion and impacts examined in this paper. Nonetheless, the size of business establishments does matter in most of those aspects. Five general propositions were tested with the results of the GEC survey, which condense the substance of the way e-commerce has developed in Mexico given the particular environmental factors playing out in this country: 1) global, more than domestic factors drive the spread of e-commerce in Mexico; 2) micro and small enterprises are the least likely to engage in e-commerce vis a vis larger establishments; 3) B-to-C e-commerce has grown more at the sectoral level than at that the national level; 4) government policies are essential for e-commerce growth; and, 5) the existence of an adequate legal framework is a crucial condition for e-commerce to develop. Propositions 1, 3, and 5 were confirmed, while 2 and 4 were only partially supported by the evidence provided by the GEC survey. [ABSTRACT FROM AUTHOR]