The electron spin resonance spectra of V2+, Mn2+, and Ni2+ doped into single crystals of CsMgBr3 and CsMgI3 have been studied at room and liquid nitrogen temperatures. The host lattices adopt the CsNiCl3 structure in which the basic structural feature is a linear array of [MX6]4− octahedra sharing faces. The site symmetry of the Mg2+ ion in this type of lattice is D3d, and the spectra can be described by an axial spin Hamiltonian. Well developed superhyperfine structure resulting from coupling with the bromine and iodine nuclei is observed in a number of the spectra at certain crystal orientations. The g values obtained for V2+ in CsMgI3 (g∥≃ g⊥≃ 2.04) are unusually large for a d3 ion and may be indicative of considerable metal to ligand delocalization. The spin Hamiltonian parameters for V2+, Mn2+, and Ni2+ in CsMgBr3 and CsMgI3, and the variation of the parameters from lattice to lattice is discussed.

Transmissible spongiform encephalopathies (TSEs) are neurological disorders that include genetic, infectious and sporadic forms of human Creutzfeldt-Jakob disease (CJD). The pathogenic agent is the prion protein that is composed of an abnormal isoform (PrP(Sc)) of a host-encoded protein (PrP(C)). Analysis of the relative amounts of PrP(Sc) glycoforms has been used to discriminate between various agents involved in TSE. The distribution and efficiency of conversion to PrP(Sc) can be influenced by differences in the expression of PrP(C). However, little attention has been given so far to the banding patterns of PrP(C). Using four different antibodies recognizing amino- and carboxyl-terminal PrP sequences we analysed the glycoforms of PrP(C) in seven regions of the human brain using brains obtained from six subjects. For determination of the staining intensities, signals were quantified by densitometry and reproducible patterns were accomplished by many repeated immunoblot analyses. When amino-terminal binding antibodies were used for detection, PrP(C) in the frontal neocortex, nucleus lentiformis, thalamus, hippocampus and cerebellum displayed a glycotype with high staining of the diglycosylated isoforms. This was different from patterns in the pons and medulla oblongata, which showed a high intensity of the nonglycosylated isoform, and PrP(C) proteins, approximately 27 kDa in size, exhibited high staining using the carboxyl-terminal binding antibodies. This intense staining followed from an overlay of full-length and truncated PrP(C) isoforms. Furthermore, we found marked differences in the expression of PrP(C). Variations in the processing of PrP(C) may lead to interregional differences in the glycoform composition of PrP(Sc) in human brains.

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Attachment of p-benzophenone side chains at N1 was found to be one of the most effective modifications for enhancing the potency of 6-azauracil against a broad spectrum of coccidia in chickens. Compound 20 was about 1000-fold more potent than 6-azauracil. Structure-activity relationships paralleled those found in a previously reported series of related analogues containing diphenyl sulfide and sulfone side chains. Drug metabolism studies showed the ketones to be reduced rapidly to carbinols, which are the prevalent species in vivo.

Recently, a. number of studies involving kinetics of complexation by the pentacyanoaquaferrate(II) ion, Fe-(CN)5OH23"(aq), have been made.1"6 Like other complexes