Spontaneous Vitiligo in a Captive Rhesus Monkey (Macaca Mulatta).

Vitiligo affects a significant portion of human and animal populations. The disease causes irregular and multifocal progressive loss of fur, skin, and mucous membrane pigmentation due to the loss or absence of melanocytes. While etiopathogenesis is not completely understood, autoimmunity, environmental, and genetic factors are implicated We present a case report on a 16-y-old female rhesus macaque (Macaca mulatta ) with depigmented areas that are progressively increasing on the skin and coat and are distributed on the head and back. Histopathology revealed alterations compatible with vitiligo characterized by the absence of melanocytes in the epidermis and dermis. The clinical history and complementary exams support this diagnosis.

Discovery of Dipeptides as Potent Botulinum Neurotoxin A Light-Chain Inhibitors.

The botulinum neurotoxin, the caustic agent that causes botulism, is the most lethal toxin known to man. The neurotoxin composed of a heavy chain (HC) and a light chain (LC) enters neurons and cleaves SNARE proteins, leading to flaccid paralysis, which, in severe occurrences, can result in death. A therapeutic target for botulinum neurotoxin (BoNT) intoxication is the LC, a zinc metalloprotease that directly cleaves SNARE proteins. Herein we report dipeptides containing an aromatic connected to the N-terminus via a sulfonamide and a hydroxamic acid at the C-terminus as BoNT/A LC inhibitors. On the basis of a structure-activity relationship study, 33 was discovered to inhibit the BoNT/A LC with an IC50 of 21 nM. X-ray crystallography analysis of 30 and 33 revealed that the dipeptides inhibit through a competitive mechanism and identified several key intermolecular interactions.

Autocatalytic Cycles in a Copper-Catalyzed Azide-Alkyne Cycloaddition Reaction.

This work describes the autocatalytic copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction between tripropargylamine and 2-azidoethanol in the presence of Cu(II) salts. The product of this reaction, tris-(hydroxyethyltriazolylmethyl)amine (N(C3N3)3), accelerates the cycloaddition reaction (and thus its own production) by two mechanisms: (i) by coordinating Cu(II) and promoting its reduction to Cu(I) and (ii) by enhancing the catalytic reactivity of Cu(I) in the cycloaddition step. Because of the cooperation of these two processes, a rate enhancement of >400× is observed over the course of the reaction. The kinetic profile of the autocatalysis can be controlled by using different azides and alkynes or ligands (e.g., ammonia) for Cu(II). When carried out in a layer of 1% agarose gel, and initiated by ascorbic acid, this autocatalytic reaction generates an autocatalytic front. This system is prototypical of autocatalytic reactions where the formation of a product, which acts as a ligand for a catalytic metal ion, enhances the production and activity of the catalyst.

The platysma window: an anatomically safe, efficient, and easily reproducible approach to neck contour in the face lift.

BACKGROUND: The cornerstone of the face lift is neck contour. The pursuit of reliable and reproducible results has led plastic surgeons to investigate a multitude of different approaches. Unfortunately, addressing neck contour can lead to complications such as injury to the great auricular nerve. The purpose of this study was to describe an efficient, safe, and reproducible technique of improving face lifts: the platysma window. METHODS: The authors use a reference point located one fingerbreadth inferior to the angle of the mandible and one fingerbreadth anterior to the anterior border of the sternocleidomastoid muscle. A two-fingerbreadth incision is made on the muscle to open a small "window," approximately 2 cm of total vertical flap length. Two figure-of-eight 4-0 Mersilene sutures are placed from the window to the mastoid fascia, spanning the great auricular nerve at McKinney's point. RESULTS: The platysma window technique is designed to minimize the complications of neck lifts-especially the risk of injury to the great auricular nerve. Placing the window inferior and anterior to these structures ensures a safe area for executing platysma tightening. This maneuver can augment a myriad of face-lifting techniques. The authors have used the maneuver described in over 200 cases, with consistently repeatable and improved neck contour results. CONCLUSIONS: Patients demand expedient and safe procedures in addition to an excellent cosmetic outcome. Plastic surgeon should try to meet their patients' needs; the authors believe the platysma window can play a role in becoming a useful method available to surgeons when addressing neck contour in face lifting.