Heat Capacity Changes and Disorder-to-Order Transitions in Allosteric Activation.

Allosteric coupling in proteins is ubiquitous but incompletely understood, particularly in systems characterized by coupling over large distances. Binding of the allosteric effector, bio-5'-AMP, to the Escherichia coli biotin protein ligase, BirA, enhances the protein's dimerization free energy by -4 kcal/mol. Previous studies revealed that disorder-to-order transitions at the effector binding and dimerization sites, which are separated by 33 Å, are integral to functional coupling.

Allosteric coupling via distant disorder-to-order transitions.

Intrinsic disorder provides a means of maximizing allosteric coupling in proteins. However, the mechanisms by which the disorder functions in allostery remain to be elucidated. Small ligand, bio-5'-AMP, binding and dimerization of the Escherichia coli biotin repressor are allosterically coupled.

Management of tonsillectomy hemorrhage: results of a survey of pediatric otolaryngology fellowship programs.

Purpose: To reach a consensus on the preoperative evaluation and management of intraoperative and postoperative tonsillectomy hemorrhage.

Method: A survey on the preoperative evaluation and the management of intraoperative and postoperative tonsillectomy hemorrhage was given to one of the faculty members at each of the pediatric otolaryngology fellowship programs in the United States.

Results And Conclusions: Seventeen surveys were distributed with 100% response.

Surgical aspects of congenital aural atresia.

Surgical repair of congenital aural atresia is a formidable task. The preoperative evaluation, embryology, surgical approaches, postoperative results, complications of surgery, and alternative methods of auditory rehabilitation of these patients are discussed in this article.

Diagnosis and management of croup and epiglottitis.

Viral croup and epiglottitis are two major inflammatory causes of airway obstruction in children. Two conditions, spasmodic croup and membranous laryngotracheobronchitis, are also frequent causes of obstruction on an inflammatory basis. Rapid diagnosis and effective management are required to ensure an uncomplicated outcome.