THE CELLULAR RECEPTOR (CD4) OF THE HUMAN IMMUNODEFICIENCY VIRUS IS EXPRESSED ON NEURONS AND GLIAL CELLS IN HUMAN BRAIN

The peculiar tropism of the human immunodeficiency virus (HIV) for T helper lymphocytes can be explained by a specific interaction between the virus and the CD4 molecule on these cells (1, 2). The tropism for T lymphocytes, however, can hardly account for the early brain infection observed in some AIDS (acquired immune deficiency syndrome) patients (3, 4). Since CD4 is also expressed on virus-susceptible non-T cell lines we wondered whether an additional expression site of CD4 could be demonstrated in neural tissue (5). To this end, CD4 expression in brain was analyzed with several different anti-CD4 mAbs, and using a CD4-specific cDNA probe in Northern blot analyses . CD4' cells and CD4-specific mRNA were found in the cerebellum, thalamus, and pons. The reactive cells could be identified as neurons as well as glial cells

DISCOVERING LARGE CONTINENTAL EMPIRES: A HISTORIAN IN SEARCH OF SPACE

Adopting an autobiographical perspective, this essay explores changes in the writing and teaching of history over the past eight decades through the introduction of the comparative dimension and the interaction of history with the social sciences. Beginning with a personal account of an early encounter with history as storytelling, the essay recounts successive exposure as an undergraduate to the comparative history of revolutions and later as an assistant professor at Northwestern University to contrasting accounts of World history and modernization theory. The analysis then centers on heated controversies that raised serious questions over the bias of Eurocentrism in the history profession. In the next stage where personal and professional intellectual development coincided in the nineteen sixties at the University of Pennsylvania, the role of the social sciences assumes a growing importance. Revisions of Marx and Weber and insights from the Annales School provided powerful incentives to organize interdisciplinary seminars and collaborative publications. The site of the third stage is the Central European University in Budapest. Here a re-organzation of the history faculty and the history curriculum introduces the comparative study of Central, Eastern and Southeastern Europe as three interrelated regions. At the same time, a related personal research agenda focuses on frontiers as an ideal spatial concept for comparative history. This leads to a broader understanding of the need to apply the geo-cultural approach of the Annales School to space outside the traditional boundaries of Europe. A research project is designed that combines a comparative study of three interrelated spatial components retaining similar features over a longue durée: the imperial rule of five continental multi-cultural societies sharing frontiers, re-defined as complex, and entangled in a competition to incorporate and assimilate borderlands on their peripheries. The project has produced ‘three volumes commemorating a lifelong commitment to a search for historical synthesis