The electronic spectra of the metallocenes, MCp2, and 1,1 '-dimethylmetallocenes, M(MeCp)2, of the first transition series ( = V, Cr, Mn, Fe, Co, Ni) have been measured between 10 and 50 cm"1 X 103 in isooctane solution. Assignments are proposed for the d-d and charge-transfer transitions observed, these being based in the latter case largely on the band shifts produced by methyl substitution. For the V, Cr, Mn, and Fe compounds the charge-transfer bands appear to correspond only to ligand -*• metal excitations (e2u -» e2g, alg, elg) but for the Co compounds (and possibly also for Ni) evidence is also found for metal ligand (elg -> e2u) transitions. For the V, Cr, Co, and Ni compounds the paramagnetic susceptibilities have been determined in toluene solution by NMR in the temperature range 183-298 K and for the parent compounds also by the Gouy method using solid samples between 83 and 298 K. The V, Cr, and Ni compounds were found to obey the Curie-Weiss law over the ranges studied, but although the V and Ni complexes yielded the spin-only values for the magnetic moment, a substantial orbital contribution was observed for CrCp2 and Cr(MeCp)2. For Co(MeCp)2 the Curie-Weiss law was obeyed over the limited range accessible, although a moment slightly greater than the spin-only value was obtained, and the parent CoCp2 gave a similar moment but deviated markedly from Curie-Weiss behavior.

We used the technique of in situ hybridization to determine if cells expressing PDGF B-chain mRNA can be detected in a model of mesangial proliferative nephritis in the rat induced with antibody directed against the Thy 1 antigen present on the mesangial cell membrane. The method involved hybridization with a digoxigenin-labeled cRNA probe for the murine PDGF B-chain followed by detection with an anti-digoxigenin-alkaline phosphatase conjugate and subsequent colorimetric reaction. In normal rats (N = 4), the majority of glomeruli (74%) were negative for PDGF B-chain mRNA, whereas 65% of glomeruli from rats with mesangial proliferative nephritis (N = 4) had segmental or diffuse staining for PDGF B-chain mRNA in a mesangial pattern. The difference, as measured using a semiquantitative scale, was significant (mean scores 0.4 +/- 0.2 vs. 1.9 +/- 0.2; scale 0 to 3+; P less than 0.001). The increase in PDGF B-chain mRNA positive cells localized to areas of hypercellularity and was associated with a significant increase in cells positive for PDGF B-chain by immunostaining with a specific monoclonal antibody (0.8 +/- 0.1 vs. 1.7 +/- 0.4, scale 0 to 3+, normal vs. diseased rats, P less than 0.005). Complement depletion, which prevents the mesangial cell proliferation, also prevented the increase in cells expressing PDGF B-chain mRNA and protein. Thus, this method of in situ hybridization can successfully detect cells expressing PDGF mRNA in active glomerulonephritis, and may be useful for detecting cells expressing genes for other growth factors and cytokines in both human and experimental models of glomerular injury.

OBJECTIVE Improvement in treatment outcome for patients with glioblastoma multiforme (GBM) requires a multifaceted approach due to dysregulation of numerous signaling pathways. The murine double minute 2 (MDM2) protein may fulfill this requirement because it is involved in the regulation of growth, survival, and invasion. The objective of this study was to investigate the impact of modulating MDM2 function in combination with front-line temozolomide (TMZ) therapy in GBM. METHODS The combination of TMZ with the MDM2 protein–protein interaction inhibitor nutlin3a was evaluated for effects on cell growth, p53 pathway activation, expression of DNA repair proteins, and invasive properties. In vivo efficacy was assessed in xenograft models of human GBM. RESULTS In combination, TMZ/nutlin3a was additive to synergistic in decreasing growth of wild-type p53 GBM cells. Pharmacodynamic studies demonstrated that inhibition of cell growth following exposure to TMZ/nutlin3a correlated with: 1) activation of the p53 pathway, 2) downregulation of DNA repair proteins, 3) persistence of DNA damage, and 4) decreased invasion. Pharmacokinetic studies indicated that nutlin3a was detected in human intracranial tumor xenografts. To assess therapeutic potential, efficacy studies were conducted in a xenograft model of intracranial GBM by using GBM cells derived from a recurrent wild-type p53 GBM that is highly TMZ resistant (GBM10). Three 5-day cycles of TMZ/nutlin3a resulted in a significant increase in the survival of mice with GBM10 intracranial tumors compared with single-agent therapy. CONCLUSIONS Modulation of MDM2/p53-associated signaling pathways is a novel approach for decreasing TMZ resistance in GBM. To the authors’ knowledge, this is the first study in a humanized intracranial patient-derived xenograft model to demonstrate the efficacy of combining front-line TMZ therapy and an inhibitor of MDM2 protein–protein interactions. http://thejns.org/doi/abs/10.3171/2016.1.JNS152513

rSPARC stimulates expression of TGF-beta1 both in vitro and in vivo. Given the closely regulated expression of SPARC, TGF-beta1, and type I collagen in several animal models of glomerulonephritis, we propose that SPARC could be one of the major mediators of the induction of TGF-beta1 in renal disease.