Hypoxic stress, like DNA damage, induces p53 protein accumulation and p53-dependent apoptosis in oncogenically transformed cells. Unlike DNA damage, hypoxia does not induce p53-dependent cell cycle arrest, suggesting that p53 activity is differentially regulated by these two stresses. Here we report that hypoxia induces p53 protein accumulation, but in contrast to DNA damage, hypoxia fails to induce endogenous downstream p53 effector mRNAs and proteins. Hypoxia does not inhibit the induction of p53 target genes by ionizing radiation, indicating that p53-dependent transactivation requires a DNA damage-inducible signal that is lacking under hypoxic treatment alone. At the molecular level, DNA damage induces the interaction of p53 with the transcriptional activator p300 as well as with the transcriptional corepressor mSin3A. In contrast, hypoxia primarily induces an interaction of p53 with mSin3A, but not with p300. Pretreatment of cells with an inhibitor of histone deacetylases that relieves transcriptional repression resulted in a significant reduction of p53-dependent transrepression and hypoxia-induced apoptosis. These results led us to propose a model in which different cellular pools of p53 can modulate transcriptional activity through interactions with transcriptional coactivators or corepressors. Genotoxic stress induces both kinds of interactions, whereas stresses that lack a DNA damage component as exemplified by hypoxia primarily induce interaction with corepressors. However, inhibition of either type of interaction can result in diminished apoptotic activity.

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Beginning in the second decade of the 19th century, Egyptian agriculture began a process of transformation from basin to perennial irrigation. This shift facilitated the practice of year-round agriculture and the cultivation of summer crops including cotton whose temporalities did not match that of the annual Nile flood. One facet of the perennially irrigated landscape was an increase in the prevalence of the parasitic diseases bilharzia (schistosomiasis) and hookworm, the symptoms of which came to constitute normative experiences of the body among those engaged in perennially irrigated agriculture. Male agricultural laborers, who most often performed the work of irrigation, were at the greatest risk of infection. This article considers the significance of agricultural labor in the continuous making and maintenance of perennially irrigated agriculture and the role of parasitic disease in producing temporal experiences of this labor.

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This piece explores the history of medicine in Egypt, the roots of an Egyptian practice of biomedicine in particular, through its historiography. In the period after World War II, the term “biomedicine” came to describe a practice of medicine defined by the close relations among clinicians, biological laboratory research, and the pharmaceutical industry in Europe and the United States. The history of medicine in Egypt and other parts of the Middle East and North Africa has long possessed close links to that in regions of Europe. In Egypt too, biomedicine has deep historical roots shaped by the influence of the nineteenth‐century Ottoman‐Egyptian state, the experience of colonialism, and the anti‐colonial objectives of the post‐colonial Egyptian state in the second half of the twentieth century. These influences were particularly important in relation to the treatment of schistosomiasis, one of Egypt's top‐ranking health problems of the twentieth century. The history of schistosomiasis demonstrates the gaps in the historiography of medicine in modern Egypt as well as how we might begin to consider the emergence of biomedical knowledge and theory at sites in Global South.