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The dawn of this century is brightened by the growing understanding and experimentation with stem cells as primary tools in the expanding regenerative medicine and tissue engineering revolution. The tradition of using prosthetic artificial implants to restore lost or damaged dental tissue will gradually be supplanted by more natural alternatives, including biological tooth replacement or induction. The practice of dentistry is likely to be revolutionized by biological therapies based on growth and differentiation factors that accelerate and/or induce a natural biological regeneration. This prospect has flourished from the gained knowledge provided by the molecular biological characterization of the genetic makeup of human cells and from a growing understanding of the effect of environmental factors. Prevention of dental diseases will also gain new ground as more insight is gained into the genetic makeup of microbial pathogens, their interactions with the host, and the host repair mechanisms. This review summarizes current knowledge, barriers, and challenges in the clinical use of stem cells with an emphasis on applications in dentistry.

Phosphorylation and dephosphorylation of proteins is an important regulatory mechanism of cell metabolism, proliferation and differentiation. The present review summarizes the known key players, their interactions, effects on physiological processes, and their role in pathology and neoplasia.

This article reviews published and original findings from two clinical trials of adoptive CD8+ T-cell immunotherapy of patients with acquired immunodeficiency syndrome (AIDS) and Kaposi's sarcoma (KS). In the first trial, AIDS patients with either KS or oral hairy leukoplakia (OHL) received five rounds of reinfusions of 10(8)-10(10) ex vivo expanded and activated autologous CD8+ T cells. Recombinant interleukin-2 (rIL-2) was coadministered only with the fifth and final infusion. Improvement, and in some cases, resolution of OHL, KS, and candidiasis was observed with no side effects. The observation that clinical improvement of KS was more pronounced when reinfusion of CD8+ T cells was followed by rIL-2 infusion led to a second clinical trial designed to examine the effect of repeated infusions of autologous CD8+ T cells with concomitant rIL-2 administration in the treatment of AIDS-related KS. Improvement of KS status was observed in four out of the eight patients studied (three partial and one complete response). The CD8+ T-cell immunotherapy protocol also provided the opportunity to comparatively study CD8+ T-cell-associated genetic programs. Baseline expression patterns of soluble and surface immune markers by CD8+ T cells from AIDS patients and uninfected controls were predominantly of the type 1 type and differed mainly at a quantitative or kinetic level. Deficiencies in immune mediator expression by CD8+ T cells from AIDS patients tended to dissipate with progression through the protocol. Findings are discussed in the context of current knowledge and therapeutic implications of CD8+ T-cell function in AIDS and neoplasia.

Benzalkonium salts comprise a group of positively charged surface-active alkylamine biocides with the general formula alkyldimethylbenzylammonium chloride or bromide. They interact with guanine nucleotide triphosphate-binding proteins (G proteins), thereby affecting signal transduction in a variety of cell types and processes. This article reviews the known and potential basic science research and clinical applications and manifestations of benzalkonium salts. Benzalkonium salts have antiproliferative effects on a variety of cells (including T cells) through G protein-dependent pathways, affect cytokine gene expression (downregulate tumor necrosis factor expression), and are also effective bactericidal, fungicidal, and virucidal agents with multisite (direct and immunologically mediated) inhibitory activity against many pathogens, including the human immunodeficiency virus (HIV), papillomavirus, and herpesviruses. Therefore, benzalkonium salts not only appear to be effective as disinfectants and spermicides but may also prove useful in the prevention and treatment of neoplasias and other disease, particularly those linked to viruses and originating at the skin or mucosal surface.