Effect of antibiotics on the oropharyngeal flora in patients with acne.

Objective: To estimate the prevalence and resistance patterns of Streptococcus pyogenes and Staphylococcus aureus in the oropharynx of individuals with acne who were using or not using antibiotic therapy.

Design: A cross-sectional study.

Setting: The Dermatology Department of the Hospital of the University of Pennsylvania, Philadelphia.

Failure to demonstrate therapeutic tachyphylaxis to topically applied steroids in patients with psoriasis.

Background: Tachyphylaxis, defined as a rapidly decreasing response to a physiologically active agent after administration of a few doses, can be well demonstrated in the experimental setting. However, tachyphylaxis in the clinical setting lacks clear demonstration.

Objective: Our purpose was to identify dermatologists' perception of the clinical incidence of tachyphylaxis and then design a prospective study that would estimate the clinical incidence of tachyphylaxis.

Expression of growth-associated protein-43 kD in Schwann cells is regulated by axon-Schwann cell interactions and cAMP.

We have examined the regulation of growth-associated protein 43 kD (GAP-43) in rat Schwann cells. In unlesioned adult nerves, GAP-43-immunoreactivity was restricted to non-myelinating Schwann cells and unmyelinated axons. When adult nerves were transected to cause permanent axotomy, previously myelinating Schwann cells expressed progressively more GAP-43-immunoreactivity over 3 weeks, and GAP-43 mRNA levels increased over a similar time course.