Doyen Nguyen

Quantitative analysis of tissues and organs can reveal large-scale patterning as well as the impact of perturbations and aging on biological architecture. Here we develop tools for imaging of single cells in intact organs and computational approaches to assess spatial relationships in 3D. In the mouse ovary, we use nuclear volume of the oocyte to read out quiescence or growth of oocyte-somatic cell units known as follicles. This in-ovary quantification of non-growing follicle dynamics from neonate to adult fits a mathematical function, which corroborates the model of fixed oocyte reserve. Mapping approaches show that radial organization of folliculogenesis established in the newborn ovary is preserved through adulthood. By contrast, inter-follicle clustering increases during aging with different dynamics depending on size. These broadly applicable tools can reveal high dimensional phenotypes and age-related architectural changes in other organs. In the adult mouse pancreas, we find stochastic radial organization of the islets of Langerhans but evidence for localized interactions among the smallest islets.

Brain death (death by neurological criteria) has been a contentious issue since its introduction into clinical medicine in 1968. It became enshrined as law in 1981 when it also received its first conceptual justification. Thereafter, other arguments, including those from pro-brain death Catholic scholars, have been advanced to shore up the practice of using brain death as the indicator for actual death. Using a multidisciplinary approach (medical evidence, Aristotelian-Thomistic anthropology, and contemporary holistic biophilosophy), this article demonstrates that brain death, both in terms of its concept and determination, contradicts the reality of the biological phenomenon of death (understood in the full sense of the word, i.e., death simpliciter) as well as the nature of the human organism viewed from either the hylomorphic or biophilosophical perspective.

This discussion note aims to address the two points which Lizza raises regarding my critique of his paper “Defining Death: Beyond Biology,” namely that I mistakenly attribute a Lockean view to his ‘higher brain death’ position and that, with respect to the ‘brain death’ controversy, both the notions of the organism as a whole and somatic integration are unclear and vague. First, it is known from the writings of constitutionalist scholars that the constitution view of human persons, a theory which Lizza also holds, has its roots in John Locke’s thought. Second, contrary to Lizza’s claims, the notions of the organism as a whole and somatic integration are both more than adequately described in the biomedical and biophilosophical literature.

In the ongoing ‘brain death’ controversy, there has been a constant push for the use of the ‘higher brain’ formulation as the criterion for the determination of death on the grounds that brain-dead individuals are no longer human beings because of their irreversible loss of consciousness and mental functions. This essay demonstrates that such a position flows from a Lockean view of human persons. Compared to the ‘consciousness-related definition of death,’ the substance view is superior, especially because it provides a holistic vision of the human person, and coheres with the perennial axiom about the ‘whole and parts.’