Using a dense PTFE membrane without primary closure to achieve bone and tissue regeneration.

The most common types of barrier membranes used for bone or tissue regeneration are made of expanded-polytetrafluoroethylene (e-PTFE) or resorbable materials, such as collagen. Both the e-PTFE and resorbable membranes require primary soft tissue coverage. This article explores the use of a dense-polytetrafluoroethylene (d-PTFE) membrane, which does not require primary soft tissue coverage. The advantages of d-PTFE in contrast to the other more commonly used types of barrier membranes and the clinical significance of these advantages for implant surgical and restorative treatment are discussed.     

Disseminated histoplasmosis with oral manifestation

Histoplasmosis is a fungal disease that affects humans and is caused by Histoplasma capsulatum. The presentation of the infection may be acute, chronic, or disseminated. The disseminated form has extrapulmonary manifestations which may include oral manifestation a. A patient with AIDS sought treatment and he had disseminated histoplasmosis with oral manifestations. The purpose of this case report and literature review is to emphasize the role the dental team has in the diagnosis of disseminated disease when a patient presents with oral manifestations associated with the disease. This case report is clinically relevant because it is not uncommon for oral manifestations to be one of the first signs of systemic disease.     

A mutation in codon 717 of the CHO-K1 elongation factor 2 gene prevents the first step in the biosynthesis of diphthamide

The histidine residue at position 715 of elongation factor 2 (EF-2) is posttranslationally modified in a series of enzymatic reactions to 2-[3-carboxyamido-3-(trimethylammonio)-propyl]histidine, which has been given the trivial name diphthamide. The diphthamide residue of EF-2 is the target site for ADP ribosylation by diphtheria toxin and Pseudomonas exotoxin A. ADP-ribosylated EF-2 does not function in protein synthesis. EF-2 that has not been posttranslationally modified at histidine 715 is resistant to ADP ribosylation by these toxins. In this report we show that a G-to-A transition in the first position of codon 717 of the EF-2 gene results in substitution of arginine for glycine and prevents addition of the side chain of diphthamide to histidine 715 of EF-2. EF-2 produced by the mutant gene is fully functional in protein synthesis.This work was supported by Public Health Service grant AI-09100 from the National Institute of Allergy and Infectious Diseases and by Biomedical Research Support Grant PHS07RR05429-27. Brian Foley is supported by a Cancer Biology Training Grant T32Ca-09286 from the National Cancer Institute.