IMP dehydrogenase, the key enzyme in de novo synthesis of purine nucleotides, is an important therapeutic target. Three inhibitors of IMP dehydrogenase reached the market; ribavirin (Rebetol) a broad-spectrum antiviral agent, which in combination with interferon-alpha is now used for treatment of hepatitis C virus infections, mizoribine (Bredinin) and mycophenolic mofetil (CellCept) have been introduced as immunosuppressants. Numerous novel inhibitors are under development. This review describes recent progress in the development of new drugs based on inhibition of IMP dehydrogenase.

In this talk we consider amplitudes for processes involving a Higgs boson, either scalar or pseudoscalar, plus four light partons. These amplitudes are relevant to the production of a Higgs boson plus two jets in hadronic collisions. They are also relevant to calculating the transverse momentum spectrum for Higgs bosons at next-to-leading order in the strong coupling. We work in the limit that the top quark is much heavier than the Higgs bosons and use effective Lagrangians for the interactions of gluons with the Higgs bosons. We present the amplitudes involving a Higgs boson and: 1) four gluons, 2) two quarks and two gluons; and 3) four quarks. We show that the pseudoscalar amplitudes are nearly identical to those for the scalar case, the only differences being the overall size and the relative signs between terms.

We consider the production of a Standard Model Higgs boson accompanied by two jets in hadronic collisions. We work in the limit that the top quark is much heavier than the Higgs boson and use an effective Lagrangian for the interactions of gluons with the Higgs boson. In addition to the previously computed four-gluon process, we compute the the amplitudes involving two quarks, two gluons and the Higgs boson and those involving four quarks and the Higgs boson. We exhibit the form of our results in the small-p_H and factorization limits. We present numerical results for root S of 14 TeV and root S of 2 TeV. We find that the dominant processes are gg -> ggH and qg -> qg H with the former (latter) contributing about 60% (40%) of the cross section at root S of 14 TeV and the two processes each contributing about half the cross section at root S of 2 TeV. All other processes are negligible at both energies.

We fabricated and tested a low temperature cell which is mounted directly on the second stage of a CTI-Cryogenics Model 22C CRYODYNE CRYOCOOLER. The vacuum system consists of a room temperature vacuum shroud, a radiation shield maintained at 77K and the cell which is mounted directly to the second stage of the cryocooler. The ultimate cell temperature is 12.4 Kelvin, and the low temperature limit increases at a rate of 5.6 Kelvin/Watt. We achieve a cell temperature of 22 Kelvin under typical experimental conditions of approximately 29 milli Torr helium, slow flowing gas, and a heated injector. The absorption path length of the cell is 3.35 cm, and the window clear aperture is 1.27 cm. We preformed a series of experiments in which we determined the translational temperatures of vibration- rotation transitions in the band of CO for different cell temperatures. The results of our tests are discussed in this paper.

Author Institution: Franklin and Marshall College, Lancaster, PA 17604-3003.; The Ohio State University, Columbus, OH 43210.