Glioblastomas are histologically and genetically heterogeneous. We have investigated to what extent histologic features reflect the genetic profile and whether they are predictive of clinical outcome. Key histologic characteristics, including major cell types (small cell, nonsmall cell), other components such as oligodendroglial components, gemistocytes, multinucleated giant cells, as well as necrosis and microvascular proliferation, of 420 cases of glioblastoma within a population-based study (1) were reassessed and correlated with patients' clinical outcome and key genetic alterations. EGFR amplification and p16 homozygous deletion were significantly more frequent in small cell glioblastomas than in nonsmall cell glioblastomas (EGFR, 46% vs 26%, p = 0.0002; p16 39% vs 25%, p = 0.0167). Multivariate analyses with adjustment for age and gender showed that small cell glioblastomas had frequent EGFR amplification and p16 deletion but infrequent PTEN mutations. An oligodendroglial component was detected in 20% of glioblastomas; these patients were significantly younger (54.4 +/- 13.6 vs 59.2 +/- 13.8 years; p = 0.0049) and survived longer (10.3 +/- 8.3 vs 8.2 +/- 8.4 months; p = 0.0647). However, multivariate analyses with adjustment for age and gender did not show the presence of an oligodendroglial component to be predictive of longer survival. After adjustment for age and gender, LOH 1p was associated with longer survival (hazard ratio, 0.7; 95% confidence interval [CI], 0.5-1.0), whereas LOH 10q was associated with shorter survival (hazard ratio, 1.4; 95% CI, 1.0-1.8) of patients with glioblastoma. Glioblastomas containing >or=5% multinucleated giant cells showed more frequent TP53 mutation and infrequent EGFR amplification than those containing <5% multinucleated giant cells (TP53, 45% vs 24%, p = 0.0001; EGFR, 24% vs 42%, p = 0.0005). Vascular proliferation was observed in all glioblastomas, whereas large ischemic and/or pseudopalisading necrosis was observed in 366 of 420 (87%) cases. Glioblastomas with necrosis were associated with older age (59.2 +/- 13.3 vs 51.6 +/- 15.3 years; p = 0.0001) and shorter survival (7.9 +/- 6.8 vs 12.9 +/- 14.2 months; p = 0.0017). Multivariate analyses with adjustment for age and gender confirmed this observation (hazard ratio, 1.5; 95% CI, 1.1-2.0). Multivariate analysis with adjustment for age and gender showed that necrosis was significantly associated with wild-type TP53 and absence of an oligodendroglial component. These results suggest that some histologic features in glioblastomas are associated with specific genetic alterations and with clinical outcome.

Background & Aims Hepatic encephalopathy (HE) is a neurologic disorder that develops during liver failure. Few studies exist investigating systemic-central signaling during HE outside of inflammatory signaling. The transcription factor Gli1, which can be modulated by hedgehog signaling or transforming growth factor β1 (TGFβ1) signaling, has been shown to be protective in various neuropathies. We measured Gli1 expression in brain tissues from mice and evaluated how circulating TGFβ1 and canonical hedgehog signaling regulate its activation. Methods Mice were injected with azoxymethane (AOM) to induce liver failure and HE in the presence of Gli1 Vivo-morpholinos (to mediate knockdown), the hedgehog inhibitor cyclopamine, smoothened Vivo-morpholinos, a smoothened agonist, or TGFβ-neutralizing antibodies. Molecular analyses were used to assess Gli1, hedgehog signaling, and TGFβ1 signaling in the liver and brain of AOM mice and HE patients. Results Gli1 expression was increased in brains of AOM mice and in HE patients. Intra-cortical infusion of Gli1 Vivo-morpholinos exacerbated the neurologic deficits of AOM mice. Measures to modulate hedgehog signaling had no effect on HE neurological decline. Levels of TGFβ1 increased in the liver and serum of mice following AOM administration. TGFβ neutralizing antibodies slowed neurologic decline following AOM administration without significantly affecting liver damage. TGFβ1 inhibited Gli1 expression via a SMAD3-dependent mechanism. Conversely, inhibiting TGFβ1 increased Gli1 expression. Conclusions Cortical activation of Gli1 protects mice from induction of HE. TGFβ1 suppresses Gli1 in neurons via SMAD3 and promotes neurologic decline. Strategies to activate Gli1 or inhibit TGFβ1 signaling might be developed to treat patients with HE.

These unique data demonstrate that the progressive neurologic impairment in Alzheimer disease is accompanied by a significant increase in senile plaque and neurofibrillary tangle counts in the frontal cortex and, possibly in some patients, by increased microglial cell activation. Cerebral amyloid angiopathy was associated with significant white matter disease.

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