NMR of laser-polarized 129Xe in blood foam.

Laser-polarized 129Xe dissolved in a foam preparation of fresh human blood was investigated. The NMR signal of 129Xe dissolved in blood was enhanced by creating a foam in which the dissolved 129Xe exchanged with a large reservoir of gaseous laser-polarized 129Xe. The dissolved 129Xe T1 in this system was found to be significantly shorter in oxygenated blood than in deoxygenated blood. The T1 of 129Xe dissolved in oxygenated blood foam was found to be approximately 21 (+/-5) s, and in deoxygenated blood foam to be greater than 40 s. To understand the oxygenation trend, T1 measurements were also made on plasma and hemoglobin foam preparations. The measurement technique using a foam gas-liquid exchange interface may also be useful for studying foam coarsening and other liquid physical properties.

Exogenous endophthalmitis initially treated without systemic antibiotics.

PURPOSE: In 1987, the authors reported the successful eradication of infection in 16 patients with culture-proven acute exogenous bacterial endophthalmitis using intravitreal but no systemic antibiotics. They retrospectively reviewed additional consecutive cases since then to determine if the initial omission of systemic antibiotics remained reasonable. METHODS: Twenty patients had culture-proven endophthalmitis. Four patients initially received systemic antibiotics for orbital cellulitis (2 patients), prevention of a possible scleral buckle infection (1 patient), and ascending cholangitis (1 patient). The remaining 16 patients were treated initially with intravitreal antibiotics only. FINDINGS: Three of these additional 16 patients ultimately required systemic antibiotics for orbital cellulitis (1 patient), infectious scleritis (1 patient), and prevention of central nervous system infection with Neisseria meningitidis (1 patient). Only in one patient who had a neglected endophthalmitis and in whom an orbital cellulitis ultimately developed were we unable to clear the intraocular infection. In the overall series of 32 patients, cultures yielded staphylococcal species in 16 eyes, gram-positive bacilli in 3, streptococcal infection in 5, gram-negative cocci in 1, and gram-negative bacilli in 7. Half of the 14 specimens (1 aqueous and 13 vitreal) collected at the time of 16 reinjections in 13 eyes yielded organisms. Half (16/32) of the eyes attained visual acuity of 20/40 or better; 87.5% (28/32) attained visual acuity of 20/400 or better. CONCLUSIONS: Therapy with intravitreal antibiotics without systemic antibiotics is reasonable, unless the infection has extended (or is at risk to extend) beyond the globe. Such evidence includes an elevated temperature or leukocyte count, corneal ring abscess, proptosis, loss of extraocular movements, scleral abscesses or infectious scleritis, and, perhaps, the presence of a scleral buckle.

[Human resources in Latin America: a historical focus on the relations among population, education, and employment]. / Los recursos humanos en la America Latina: enfoque historico de las relaciones entre poblacion, educacion y empleo.

PIP: Analysis of human resources has a history of almost 3 decades in Latin America. This method of assessing temporary and structural balances and imbalances between population, education, and employment began in the 1960s with recognition of the role of education in development. The human resources perspective tended to be centered more on the availability or supply of resources as affected by educational planning than on occupational requirements or demand. It was also centered on problems of educational investment and planning, leaving aside other basic aspects of human resources development such as health or nutrition. The notion of human resources has progressed in Latin America from imitation of the educational systems of the industrialized countries to attempts to project future occupational structures in Latin America and to adjust training and educational programs accordingly. But longterm projection of occupational structures is very difficult in Latin America primarily because of the unstable and dependent status of Latin American economies which leave them at the mercy of changes in the central countries. A series of studies in the mid-1970s argued for the need to revise the dominant development strategies in order to eliminate poverty within 50 years, implying increased attention to human resources. The economic crisis of the 1970s and beyond had deflected attention away from the actions necessary to reach this goal. Latin America, despite considerable economic progress and modernization, still is incapable of providing productive employment for a large proportion of its population. Around 50% of the economically active population was unemployed or underemployed in 1980. Recent studies have revealed several peculiarities in the occupational dynamics of countries, and they never have the proportion of highly skilled workers that the developed countries do. Urbanization and growth of the tertiary sector are rapid. Where agriculture has modernized, rural employment has declined abruptly. The residual category of labor in the informal sector is large and growing rapidly in countries of the region. These distortions express the structural incapacity of economies on the region to employ their available human resources in a context of rapid population growth and considerable (though still insufficient) investment in education. A different development strategy, oriented toward satisfaction of basic needs of the population, would mobilize human resources and create employment. In the case of educaiton, available data point to a continuing disarticulation between population dynamics, employment, and education. The existence of some 40 million illiterates in Latin America and the Caribbean and the wasted investment in large numbers of highly educated persons who either emigrate or remain underemployed in their own countries express 2 facets of this problem.^ieng