Faculty Bibliography

The physiological and cell biological aspects of the Coxsackie-Adenovirus Receptor (CAR) is discussed in this review. The receptor obviously recognizes the group C adenoviruses in vivo, but also fibers from other groups except group B in vitro. The latter viruses seem to utilize a different receptor. The receptor accumulates at, or close to, the tight junction in polarized epithelial cells and probably functions as a cell-cell adhesion molecule. The cytoplasmic tail of the receptor is not required for virus attachment and uptake. Although there is a correlation between CAR and uptake of adenoviruses in several human tumor cells, evidence of an absolute requirement for integrins has not been forthcoming. The implication of these findings for adenovirus gene therapy is discussed

The Makapansgat Limeworks is a significant Pliocene site both for its sample of 35 hominin fossils as well as its wealth of fossil fauna. The lithological and paleontological successions reveal local environmental changes that are important for understanding the context of hominin evolution in southern Africa. Yet most of the site's fossils were found in dumps left behind by quarry operations, and the paleoecological interpretations rest upon debatable assumptions about the original fossil provenience. We have recently initiated systematic paleoanthropological excavations at Makapansgat to recover well provenanced fossils in order to: 1) assess whether faunal successions are discernable in the Makapansgat sequence; 2) assist environmental interpretations of the site; 3) and potentially recover the oldest hominins in South Africa, roughly coincident with Australopithecus afarensis in East Africa. This paper presents a summary of our current paleoenvironmental research at the Limeworks and preliminary results of ongoing in situ excavations.

Gender differences exist in the development of the nigrostriatal dopamine system, and in the incidence and course of pediatric and adult neuropsychiatric diseases in which this system is implicated. The medium size spiny neuron (MSN) is the major output neuron of the caudate nucleus. It receives a large dopaminergic input from the substantia nigra, and 96% of the MSNs express DARPP-32, a dopamine and cyclic AMP-regulated phosphoprotein and key mediator of dopamine function. There are few examples, however, of direct effects of sex hormones, including 17beta-estradiol (E(2)), on the MSN. We report that in vitro, E(2) (10-50 nM) promotes MSN phenotypic maturation, as determined by increased soma size, neurite length, and DARPP-32 protein levels. Treatment with the 'anti-estrogen' ICI 182,780 or the partial-agonist tamoxifen also increases DARPP-32 levels, but when added to E(2), ICI 182,780 only prevents the increase in DARPP-32 levels and increase in soma size and neurite length. Surprisingly, maturation effects are more robust in cells derived exclusively from female embryos. Western blot analysis of protein lysates and immunocytochemistry of cultured MSNs reveals the presence of the estrogen receptor beta (ERbeta). These data suggest that ERbeta may mediate the differentiating effect of E(2) on embryonic MSNs, and provide new avenues of investigation for the role of sex hormones in the development of the striatum and in diseases affecting the basal ganglia

A method of creating pseudopure spin states in large clusters of coupled spins is described. It is based on filtering multiple-quantum coherence of the highest order, followed by a time-reversal period and partial saturation. Experimental demonstration is presented for a cluster of six dipolar-coupled proton spins of a benzene molecule in a liquid crystalline matrix, and the details of spin dynamics are studied numerically.