10 research outputs found

    Traumatic rupture of thoracic epidural capillary hemangioma resulting in acute neurologic deficit: illustrative case

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    BackgroundThoracic epidural capillary hemangioma is exceedingly rare, with only a few reported cases. The typical presentation usually includes chronic, progressive symptoms of spinal cord compression in middle-aged adults. To the authors' knowledge, this case is the first report in the literature of acute traumatic capillary hemangioma rupture.ObservationsA 22-year-old male presented with worsening lower extremity weakness and paresthesias after a fall onto his spine. Imaging showed no evidence of spinal fracture but revealed an expanding hematoma over 24 hours. Removal of the lesion demonstrated a ruptured capillary hemangioma.LessonsThis unique case highlights a rare occurrence of traumatic rupture of a previously unknown asymptomatic thoracic capillary hemangioma in a young adult

    CDK 4/6 inhibitors for the treatment of meningioma.

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    Meningiomas are the most common non-metastatic brain tumors, and although the majority are relatively slow-growing and histologically benign, a subset of meningiomas are aggressive and remain challenging to treat. Despite a standard of care that includes surgical resection and radiotherapy, and recent advances in meningioma molecular grouping, there are no systemic medical options for patients with meningiomas that are resistant to standard interventions. Misactivation of the cell cycle at the level of CDK4/6 is common in high-grade or molecularly aggressive meningiomas, and CDK4/6 has emerged as a potential target for systemic meningioma treatments. In this review, we describe the preclinical evidence for CDK4/6 inhibitors as a treatment for high-grade meningiomas and summarize evolving clinical experience with these agents. Further, we highlight upcoming clinical trials for patients meningiomas, and discuss future directions aimed at optimizing the efficacy of these therapies and selecting patients most likely to benefit from their use

    Jet-Cooled Spectroscopy of the α‑Methylbenzyl Radical: Probing the State-Dependent Effects of Methyl Rocking Against a Radical Site

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    The state-dependent spectroscopy of α-methylbenzyl radical (α-MeBz) has been studied under jet-cooled conditions. Two-color resonant two-photon ionization (2C-R2PI), laser-induced fluorescence, and dispersed fluorescence spectra were obtained for the D<sub>0</sub>–D<sub>1</sub> electronic transition of this prototypical resonance-stabilized radical in which the methyl group is immediately adjacent to the primary radical site. Extensive Franck–Condon activity in hindered rotor levels was observed in the excitation spectrum, reflecting a reorientation of the methyl group upon electronic excitation. Dispersed fluorescence spectra from the set of internal rotor levels are combined with the excitation spectrum to obtain a global fit of the barrier heights and angular change of the methyl group in both D<sub>0</sub> and D<sub>1</sub> states. The best-fit methyl rotor potential in the ground electronic state (D<sub>0</sub>) is a flat-topped 3-fold potential (V<sub>3</sub>″ = 151 cm<sup>–1</sup>, V<sub>6</sub>″ = 34 cm<sup>–1</sup>) while the D<sub>1</sub> state has a lower barrier (V<sub>3</sub>′ = 72 cm<sup>–1</sup>, V<sub>6</sub>′ = 15 cm<sup>–1</sup>) with Δφ = ± π/3, π, consistent with a reorientation of the methyl group upon electronic excitation. The ground state results are compared with calculations carried out at the DFT B3LYP level of theory using the 6-311+G­(d,p) basis set, and a variety of excited state calculations are carried out to compare against experiment. The preferred geometry of the methyl rotor in the ground state is <i>anti</i>, which switches to <i>syn</i> in the D<sub>1</sub> state and in the cation. The calculations uncover a subtle combination of effects that contribute to the shift in orientation and change in barrier in the excited state relative to ground state. Steric interaction favors the <i>anti</i> conformation, while hyperconjugation is greater in the <i>syn</i> orientation. The presence of a second excited state close by D<sub>1</sub> is postulated to influence the methyl rotor properties. A resonant ion-dip infrared (RIDIR) spectrum in the alkyl and aromatic CH stretch regions was also recorded, probing in a complementary way the state-dependent conformation of α-MeBz. Using a scheme in which infrared depletion occurs between excitation and ionization steps of the 2C-R2PI process, analogous infrared spectra in D<sub>1</sub> were also obtained, probing the response of the CH stretch fundamentals to electronic excitation. A reduced-dimension Wilson G-matrix model was implemented to simulate and interpret the observed infrared results. Finally, photoionization efficiency scans were carried out to determine the adiabatic ionization threshold of α-MeBz (IP = 6.835 ± 0.002 eV) and provide thresholds for ionization out of specific internal rotor levels, which report on the methyl rotor barrier in the cation state

    Epigenetic regulation of ageing: linking environmental inputs to genomic stability

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