Polyglutamine Disease Modeling: Epitope Based Screen for Homologous Recombination using CRISPR/Cas9 System.

We have previously reported the genetic correction of Huntington's disease (HD) patient-derived induced pluripotent stem cells using traditional homologous recombination (HR) approaches. To extend this work, we have adopted a CRISPR-based genome editing approach to improve the efficiency of recombination in order to generate allelic isogenic HD models in human cells. Incorporation of a rapid antibody-based screening approach to measure recombination provides a powerful method to determine relative efficiency of genome editing for modeling polyglutamine diseases or understanding factors that modulate CRISPR/Cas9 HR.

Structural basis for the prion-like MAVS filaments in antiviral innate immunity.

Mitochondrial antiviral signaling (MAVS) protein is required for innate immune responses against RNA viruses. In virus-infected cells MAVS forms prion-like aggregates to activate antiviral signaling cascades, but the underlying structural mechanism is unknown. Here we report cryo-electron microscopic structures of the helical filaments formed by both the N-terminal caspase activation and recruitment domain (CARD) of MAVS and a truncated MAVS lacking part of the proline-rich region and the C-terminal transmembrane domain.

Novel modification of tracheostomy tube to allow speech and manage tracheal stenosis.

Mid-tracheal, postintubation stenosis can be managed with an extended length tracheostomy tube to bypass the stenotic area. However these extra-long tracheostomy tubes are not fenestrated, and when the stenotic tracheal lumen sits against the tracheostomy tube, phonation is not possible as there is no translaryngeal airflow. A 59-year-old man developed distal tracheal stenosis following a prolonged intubation and tracheostomy after a motorcycle accident.

Tendon sheath fibroma in the thigh.

Tendon sheath fibromas are rare, benign soft tissue tumors that are predominantly found in the fingers, hands, and wrists of young adult men. This article describes a tendon sheath fibroma that developed in the thigh of a 70-year-old man, the only known tendon sheath fibroma to form in this location. Similar to tendon sheath fibromas that develop elsewhere, our patient's lesion presented as a painless, slow-growing soft tissue nodule.

Recurrent lipoma-like hibernoma.

This is the fifth report of the rare lipoma-like variant of hibernoma, the 19th case reported, and the first documented as recurring after excision. Our patient was a 56-year-old man whose painful lipoma-like hibernoma (LLH) in the pelvis/buttock was initially treated with marginal excision 15 years earlier. Nine years after treatment, the LLH recurred locally.

Early pleomorphic hyalinizing angiectatic tumor: precursor or distinct lesion?

Early pleomorphic hyalinizing angiectatic tumor is a rare and recently described soft tissue lesion. Originally believed to be a precursor lesion to neoplastic pleomorphic hyalinizing angiectatic tumor, and possibly identical to hemosiderotic fibrohistiocytic lipomatous lesion/tumor, there have been recent suggestions that it is distinct from pleomorphic hyalinizing angiectatic tumor and is instead a reactive process. This article reports a case of a mass in the foot of a 45-year-old woman, which is 1 of only 15 published cases of early pleomorphic hyalinizing angiectatic tumor and is the first case to describe its radiographic appearance.

Fibroma of tendon sheath in the knee: a report of three cases and literature review.

Fibroma of tendon sheath (FTS) is a rare and benign soft-tissue tumor. It is predominantly found in the fingers, hands, and wrists of young, adult males. We describe a series of three cases all presenting in the atypical knee location.