The cytokines IL-3 and GM-CSF regulate the transcriptional activity of retinoic acid receptors in different in vitro models of myeloid differentiation.

The disruption of retinoic acid receptor (RAR) activity that characterizes human acute promyelocytic leukemia (APL) is associated with a block to granulocytic differentiation indicating that RARs are critical regulators of normal myeloid differentiation. Nevertheless, how RAR activity might be regulated in the presumably homogenous concentration of retinoids in blood and bone marrow and how these receptors might interact with specific hematopoietic cytokines to regulate normal myeloid differentiation remain unclear. Here, using several cytokine-dependent in vitro models of myeloid development, it was observed that specific hematopoietic cytokines that normally regulate myeloid lineage commitment and differentiation (interleukin-3 and granulocyte-macrophage colony-stimulating factor) trigger the enhancement of both ligand-dependent and ligand-independent transcriptional activity of both endogenous and exogenous (transiently transfected) RARs.

Oral complications associated with immunosuppression and cancer therapies.

The oral manifestations of oropharyngeal infection in immunocompromised patients present a particular challenge for both medical and dental professionals because clinical signs and symptoms may be minimal and accurate diagnosis and appropriate treatment may be difficult. Effective control of infection and management of oral symptoms are important and may be achieved by the judicious use of topical and systemic agents and by maintaining good oral hygiene. Prevention of mucosal breakdown, suppression of microbial colonization, control of viral reactivation, and effective management of severe xerostomia are all critical steps to reduce the overall morbidity and mortality of oromucosal infections in the severely immunocompromised patient.

Retinoid X receptor (RXR) agonist-induced activation of dominant-negative RXR-retinoic acid receptor alpha403 heterodimers is developmentally regulated during myeloid differentiation.

The multiple biologic activities of retinoic acid (RA) are mediated through RAR and retinoid X receptor (RXR) nuclear receptors that interact with specific DNA target sequences as heterodimers (RXR-RAR) or homodimers (RXR-RXR). RA receptor activation appears critical to regulating important aspects of hematopoiesis, since transducing a COOH-terminally truncated RARalpha exhibiting dominant-negative activity (RARalpha403) into normal mouse bone marrow generates hematopoietic growth factor-dependent cell lines frozen at the multipotent progenitor (EML) or committed promyelocyte (MPRO) stages. Nevertheless, relatively high, pharmacological concentrations of RA (1 to 10 microM) overcome these differentiation blocks and induce terminal granulocytic differentiation of the MPRO promyelocytes while potentiating interleukin-3 (IL-3)-induced commitment of EML cells to the granulocyte/monocyte lineage.

Effects of gastroesophageal reflux on the oral cavity.

The effects of chronic exposure of the oral cavity to gastric acid can be many and varied. Soft tissue symptoms (nonspecific burning and sensitivity) have been mentioned in the literature, but pathognomonic soft tissue lesions have not been documented. Dental erosion can be considered to be the predominant oral manifestation of gastroesophageal reflux disease.

Compliance to recommended infection control procedures: changes over six years among British Columbia dentists.

Over the last decade, in response to the heightened awareness of HBV and HIV infections, world health authorities have produced specific infection control recommendations for dental practices. Surveys have been done in various countries to investigate the level of compliance to these recommendations. This paper reports on the changes in compliance over a six year period among British Columbia dentists, as indicated from four volunteer surveys conducted between 1987 and 1993.

Radiographic evaluation of occlusal caries: effect of training and experience.

The purpose of this study was to investigate what effect differing levels of didactic education and clinical experience have on the ability to diagnose occlusal caries from radiographs. Freshman and senior dental students and dental school faculty were asked to evaluate bitewing radiographs for the presence of occlusal caries and for a recommendation for restorative treatment. The agreement between histologic and radiographic diagnosis was assessed by calculating sensitivity, specificity, accuracy, and interexaminer agreement.