An Unusual Case of Pinna Squamous Cell Carcinoma Arising Shortly after Resection of Atypical Fibroxanthoma.

Objective: To report a unique case of pinna squamous cell carcinoma (SCC) arising shortly after resection of atypical fibroxanthoma (AFX) at the same site.

Case Report: An 81-year-old gentleman presented with a nodular right pinna lesion. This was excised, and histology confirmed AFX.

Airway management in patients with subglottic stenosis: experience at an academic institution.

We describe a pilot study investigating the airway techniques used in the anesthetic management of subglottic stenosis. We searched the electronic clinical information database of the University of Michigan Health System for cases of subglottic stenosis in patients undergoing surgery. Demographics, airway techniques, incidence of hypoxemia, and technique failure were extracted from 159 records.

T-loop phosphorylation stabilizes the CDK7-cyclin H-MAT1 complex in vivo and regulates its CTD kinase activity.

Cyclin-dependent kinase (CDK)7-cyclin H, the CDK-activating kinase (CAK) and TFIIH-associated kinase in metazoans can be activated in vitro through T-loop phosphorylation or binding to the RING finger protein MAT1. Although the two mechanisms can operate independently, we show that in a physiological setting, MAT1 binding and T-loop phosphorylation cooperate to stabilize the CAK complex of Drosophila. CDK7 forms a stable complex with cyclin H and MAT1 in vivo only when phosphorylated on either one of two residues (Ser164 or Thr170) in its T-loop.

Reciprocal activation by cyclin-dependent kinases 2 and 7 is directed by substrate specificity determinants outside the T loop.

Cyclin-dependent kinase 7 (CDK7) is the catalytic subunit of the metazoan CDK-activating kinase (CAK), which activates CDKs, such as CDC2 and CDK2, through phosphorylation of a conserved threonine residue in the T loop. Full activation of CDK7 requires association with a positive regulatory subunit, cyclin H, and phosphorylation of a conserved threonine residue at position 170 in its own T loop. We show that threonine-170 of CDK7 is phosphorylated in vitro by its targets, CDC2 and CDK2, which also phosphorylate serine-164 in the CDK7 T loop, a site that perfectly matches their consensus phosphorylation site.