Dihydrouridine (D) is a highly conserved modified base found in tRNAs from all domains of life. Dihydrouridine synthase (Dus) catalyzes the D formation of tRNA through reduction of uracil base with flavin mononucleotide (FMN) as a cofactor. Here, we report the crystal structures of Thermus thermophilus Dus (TthDus), which is responsible for D formation at positions 20 and 20a, in complex with t...

The ionizing radiation (IR) dose that yields 20% survival (D20) of Shewanella oneidensis MR-1 is lower by factors of 20 and 200 than those for Escherichia coli and Deinococcus radiodurans, respectively. Transcriptome analysis was used to identify the genes of MR-1 responding to 40 Gy (D20). We observed the induction of 170 genes and repression of 87 genes in MR-1 during a 1-h recovery period af...

We assessed the time-course of adjuvant arthritis (AA) in Lewis rats, using biotelemetry to monitor the rat's spontaneous locomotor activity and body temperature, and studied the evolution of the arthritic index, circulating concentrations of inflammation-promoting cytokines, cartilage proteoglycan synthesis, and the effect of indomethacin as a cyclooxygenase inhibitor to evaluate prostaglandin...

The production of luteal oxytocin in ewes, resulting from the intrajugular injection of 200 micrograms of PGF2 alpha, could be determined by the increase in intramammary pressure. This simple indirect method of measuring the activity of the corpus luteum enabled easy detection of renewed post-partum ovulation or the onset of pregnancy. The response was monitored every two days between Days 0 an...

Converged quantum mechanical vibrational-rotational partition functions and free energies are calculated using realistic potential energy surfaces for several chalcogen dihydrides (H20, D20, H 2S, H2Se) over a wide range of temperatures (600-4000 K). We employ an adaptively optimized Monte Carlo integration scheme for computing vibrational-rotational partition functions by the Fourier path-inte...

Heavy water has been used as a tool to study the role of water in the association-dissociation equilibrium of subunit proteins. In the case of lactate dehydrogenase, DzO was found to stabilize the enzyme at low ionic strength and inhibit subunit interchange between heartand muscle-type enzyme in solution. When frozen, however, subunit interchange occurred to a similar extent in either DzO or Hz...

Iron overload has been implicated in decreased bone mineral density. However, the effect of iron overload on osteoblast lineage cells remains poorly understood. The purpose of this study was to examine osteoblast differentiation, function, and apoptosis in iron-loaded cells from fetal rat calvaria. Cells were incubated with media supplemented with 0-10 microM ferrous sulfate (FeSO(4)) during di...

The effect of various anti-microtubular agents on alloxan stimulation and inhibition of a subsequent glucose-induced insulin release was investigated using in vitro incubation and perifusion of rat isolated islets of Langerhans. Five minute exposure of islets to alloxan (20 mg/dl) induced a transient burst of insulin release which was eliminated by the pretreatment of islets by heavy water (D20...

Heavy water has been used as a tool to study the role of water in the association-dissociation equilibrium of subunit proteins. In the case of lactate dehydrogenase, DzO was found to stabilize the enzyme at low ionic strength and inhibit subunit interchange between heartand muscle-type enzyme in solution. When frozen, however, subunit interchange occurred to a similar extent in either DzO or Hz...