Cerebral neoplasms in L-2 hydroxyglutaric aciduria: 3 new cases and meta-analysis of literature data.

SUMMARY: Increasing evidence suggests that patients with L2-HGA have a predisposition to cerebral neoplasms. This may be related to the pathologic accumulation of L2-HG because high amounts of 2-HG have been found in brain neoplasms that have IDH1 mutations. Our experience, on the basis of 11 previously unreported cases of L2-HGA, 3 of which developed cerebral neoplasms during the course of the disease, also supports an association between L2-HGA and cerebral neoplasms. We conducted a meta-analysis of published data, and we identified 295 patients (including our 11 patients) with L2-HGA. In 14 patients, the metabolic disorder was associated with cerebral neoplasms, suggesting an approximately 5% prevalence rate of CNS neoplasms in patients with L2-HGA; nonetheless, it may still be an underestimate. L2-HGA is an important disease "model" that provides further evidence to support the recently proposed pathogenetic role of 2-HG in the development of cerebral neoplasms.

Tuning indistinguishability in Bose-Einstein condensation and new atomic states.

The concept of indistinguishability is the key element in quantum statistics. But, are particles really either indistinguishable or distinguishable? Most works begin with the premise that all the particles, for example, in a quantum gas, are indistinguishable. Can we vary the degree of distinguishability in some controlled, continuous manner and see how it affects the behavior of the quantum gas, such as Bose-Einstein condensation (BEC)? We have found a complex parameter with a definite phase that does just that. As it deviates from zero, a gas mixture of originally indistinguishable bosons would divide into several distinct species that undergo BEC individually. Each species is found to be in a new type of atomic state whose spin structure adapts itself to the prevailing densities of the gases in the mixture.