Oral chronic graft-versus-host disease: current pathogenesis, therapy, and research.

Optimal management of complex autoimmune diseases requires a multidisciplinary medical team including dentists to care for lesions of the oral cavity. In this review, we discuss the presentation, prevalence, diagnosis, and treatment of oral manifestations in chronic graft-versus-host disease (cGVHD), which is a major late complication in patients treated by allogeneic hematopoietic stem cell transplantation. We assess current general knowledge of systemic and oral cGVHD and present general treatment recommendations based on literature review and our clinical experience. Additionally, we review areas where the understanding of oral cGVHD could be improved by further research and address tools with which to accomplish the long-term goal of providing better health and quality of life to patients with cGVHD.

Repeated social defeat activates dendritic cells and enhances Toll-like receptor dependent cytokine secretion.

Stress hormones significantly impact dendritic cell (DC) activation and function, typically in a suppressive fashion. However, a social stressor termed social disruption (SDR) has been shown to induce an increase in inflammatory responses and a state of glucocorticoid resistance in splenic CD11b+ monocytes. These experiments were designed to determine the effects of SDR on DC activation, Toll-like receptor-induced cytokine secretion, and glucocorticoid sensitivity. Compared to cells obtained from control animals, splenic DCs from SDR mice displayed increased levels of MHC I, CD80, and CD44, indicative of an activated phenotype. In addition, DCs from SDR mice produced comparatively higher TNF-alpha, IL-6, and IL-10 in response to in vitro stimulation with LPS and CpG DNA. Increased amounts of TNF-alpha and IL-6 were also evident in SDR DC cultures stimulated with poly(I:C). Furthermore, as shown previously in CD11b+ monocytes, the CD11c+ DCs obtained from SDR mice were glucocorticoid resistant. Taken together, the data suggest that social stress, in the absence of any immune challenge, activates DCs, increases DC cytokine secretion in response to Toll-specific stimuli and renders DCs glucocorticoid resistant.

Epithelial Cell Lineage and Signaling in Murine Salivary Glands.

Maintaining salivary gland function is critical for oral health. Loss of saliva is a common side effect of therapeutic irradiation for head and neck cancer or autoimmune diseases such as Sjögren's syndrome. There is no curative treatment, and current strategies proposed for functional regeneration include gene therapy to reengineer surviving salivary gland tissue, cell-based transplant therapy, use of bioengineered glands, and development of drugs/biologics to stimulate in vivo regeneration or increase secretion. Understanding the genetic and cellular mechanisms required for development and homeostasis of adult glands is essential to the success of these proposed treatments. Recent advances in genetic lineage tracing provide insight into epithelial lineage relationships during murine salivary gland development. During early fetal gland development, epithelial cells expressing keratin 14 (K14) Sox2, Sox9, Sox10, and Trp63 give rise to all adult epithelium, but as development proceeds, lineage restriction occurs, resulting in separate lineages of myoepithelial, ductal, and acinar cells in postnatal glands. Several niche signals have been identified that regulate epithelial development and lineage restriction. Fibroblast growth factor signaling is essential for gland development, and other important factors that influence epithelial patterning and maturation include the Wnt, Hedgehog, retinoic acid, and Hippo signaling pathways. In addition, other cell types in the local microenvironment, such as endothelial and neuronal cells, can influence epithelial development. Emerging evidence also suggests that specific epithelial cells will respond to different types of salivary gland damage, depending on the cause and severity of damage and the resulting damaged microenvironment. Understanding how regeneration occurs and which cell types are affected, as well as which signaling factors drive cell lineage decisions, provides specific targets to manipulate cell fate and improve regeneration. Taken together, these recent advances in understanding cell lineages and the signaling factors that drive cell fate changes provide a guide to develop novel regenerative treatments.

Oral disease profiles in chronic graft versus host disease.

At least half of patients with chronic graft-versus-host-disease (cGVHD), the leading cause of morbidity and non-relapse mortality after allogeneic stem cell transplantation, have oral manifestations: mucosal lesions, salivary dysfunction, and limited mouth-opening. cGVHD may manifest in a single organ or affect multiple organ systems, including the mouth, eyes, and the skin. The interrelationship of the 3 oral manifestations of cGVHD with each other and with the specific manifestations of extraoral cGVHD has not been studied. In this analysis, we explored, in a large group of patients with cGVHD, the potential associations between: (1) oral mucosal disease and erythematous skin disease, (2) salivary gland dysfunction and lacrimal gland dysfunction, and (3) limited mouth-opening and sclerotic skin cGVHD. Study participants, enrolled in a cGVHD Natural History Protocol (NCT00331968, n = 212), underwent an oral examination evaluating: (1) mucosal cGVHD [NIH Oral Mucosal Score (OMS)], (2) salivary dysfunction (saliva flow and xerostomia), and (3) maximum mouth-opening measurement. Parameters for dysfunction (OMS > 2, saliva flow ≤ 1 mL/5 min, mouth-opening ≤ 35 mm) were analyzed for association with skin cGVHD involvement (erythema and sclerosis, skin symptoms), lacrimal dysfunction (Schirmer's tear test, xerophthalmia), Lee cGVHD Symptom Scores, and NIH organ scores. Oral mucosal disease (31% prevalence) was associated with skin erythema (P < 0.001); salivary dysfunction (11% prevalence) was associated with lacrimal dysfunction (P = 0.010) and xerostomia with xerophthalmia (r = 0.32, P = 0.001); and limited mouth-opening (17% prevalence) was associated with skin sclerosis (P = 0.008) and skin symptoms (P = 0.001). There was no association found among these 3 oral cGVHD manifestations. This analysis supports the understanding of oral cGVHD as 3 distinct diseases: mucosal lesions, salivary gland dysfunction, and mouth sclerosis. Clear classification of oral cGVHD as 3 separate manifestations will improve clinical diagnosis, observational research data collection, and the definitions of outcome measures in clinical trials.

Improved orthopaedic bone cement formulations based on rubber toughening.

Poly(methylmethacrylate) (PMMA) bone cements have been used for the fixation of hip and knee implants since the early 1960s. Aseptic loosening, related to fracture of the PMMA, continues to be the primary mode of failure for these prostheses. Failed prostheses must be replaced causing additional expense and patient trauma. Furthermore, the average lifetime of the revised prosthesis is significantly lower than that of a primary prosthesis. Recent work by Moseley and co-workers led to the development of a promising new rubber toughened cement. It is comprised of a matrix of the traditional PMMA with dispersed rubber particles to modify mechanical properties and, in particular, improve fracture toughness. The fracture toughness of the experimental material was 167% greater than the toughness of a nontoughened control; however, the elastic modulus and compressive strength were reduced. The reductions in properties should not pose a clinical problem based on results of the implant model reported by Moseley. More serious concerns were mixing and delivery problems and high residual monomer concentrations. The formulation and chemical/mechanical characterization of new toughened acrylic formulations that have residual monomer levels equivalent to Simplex and better mixing properties are reported.

Stability in the Federal Employees Health Benefits Program.

Recently the Federal Employees Health Benefits Program has been the subject of much discussion in Washington as a result of the rather large premium increases in 1982 and 1983, the delayed open season of 1981, and the benefit reductions. Enrollees responded in May 1982 to the changes; a record number switched plans. It appears that enrollees were simply responding to the new premiums and benefits. In this paper we describe the economic incentives faced by enrollees in the FEHBP. We find that, due to the strong incentives for enrollees to leave certain high-cost plans, continued instability should be expected. In fact, the disparity between expected benefits and premium is so great for some plans (e.g. the Blue Cross high-option) that their survival is questionable. This lack of stability raises important questions about the viability of some pro-competition proposals involving multiple-insurer systems.

Capillary electrophoresis of associative diblock copolymers.

Water soluble diblock copolymers composed of a long poly(styrene sulfonate) chain (between 200 and 400 monomers) and a short poly(ethylene propylene) or poly(tert.-butylstyrene) hydrophobic end (20-50 monomers) are highly associative and form micelles in aqueous solution. The micelles are composed of a small hydrophobic core and a polyelectrolyte corona, the dimensions of which can be estimated by neutron and light scattering. These physical techniques are, however, not amenable to discriminate easily between the free copolymer and the copolymer micelle. Capillary electrophoresis was implemented in this work as a new and effective tool to investigate the behaviour of such associative copolymer systems. Since the rate of exchange between the micellised and free states is very slow in comparison with the time scale of the electrophoretic process, the electropherograms of the diblock copolymers obtained in plain aqueous borate buffers exhibit two peaks assigned to the two states mentioned above. The identification of the two peaks was first made on the basis of the retention orders of the two peaks equally obtained in similar conditions by size-exclusion chromatography. The copolymer micelles appeared to have a smaller electrophoretic mobility than the free copolymers. This peak assignment is also consistent with the observed ratio of the time-corrected peak areas and peak dispersions. The effects of the copolymer concentration, electric field, temperature and hydroorganic composition of the medium was also studied. Such systems do not exhibit a defined concentration threshold equivalent to a classical critical micelle concentration. Adding methanol to the electrolyte resulted in the progressive loss of baseline return between the two peaks, which might be attributed to a slight increase in the rate of exchange between the two states. Finally, adding a neutral surfactant to the electrolyte at a concentration in excess of its critical micelle concentration resulted in a decrease in the electrophoretic mobility of the peak attributed to the free copoplymer, while the electrophoretic mobility of the copolymer micelle remained unperturbed.

Biased selection in the Federal Employees Health Benefits Program.

The existence of biased selection in health insurance markets has long been assumed by economic theorists as well as seen between classes of health plans. In this paper, we use a model of the premium rate that takes into consideration the effects of moral hazard to make empirical estimates of the extent of selection in the Federal Employees Health Benefits Program. We find that biased selection has raised the premium of the Blue Cross Plan high-option coverage by 21% and lowered the premium of the low-option coverage by 29%, both relative to premiums that would have been charged in the absence of selection.

Validation of the National Institutes of Health chronic GVHD Oral Mucosal Score using component-specific measures.

Oral chronic GVHD (cGVHD) is a common, late complication of alloSCT that is associated with significant patient morbidity. The NIH Oral Mucosal Score (NIH OMS) was developed to assess oral cGVHD therapeutic response, but has not been fully validated. This study's purpose was to conduct a rigorous construct validity and internal consistency analysis of this score and its components (erythema, lichenoid, ulcers, mucoceles) using established measures of oral pain, oral function, oral-related quality-of-life, nutrition and laboratory parameters in 198 patients with cGVHD. The construct validity of the NIH OMS was supported: a moderate correlation was observed between NIH OMS and mouth pain (rho=0.43), while a weaker correlation was observed with low albumin (rho=-0.26). Total NIH OMS, erythema and lichenoid components were associated with malnutrition, oral pain and impaired oral QOL, while ulcers were only associated with oral pain. No associations were found between mucoceles and any indicator evaluated, including salivary function or xerostomia. Kappa determined between scale components was low overall (all 0.35), supporting a conclusion that each component measures a distinct manifestation of oral cGVHD. This study supports the use of the NIH OMS and its components (erythema, lichenoid and ulcerations) to measure clinician-reported severity of oral cGVHD.

Malnutrition in patients with chronic GVHD.

Malnutrition is a known complication of chronic GVHD (cGVHD), but has not been well described in the context of organ-specific manifestations and the recent National Institutes of Health (NIH) criteria. Here, 210 cGVHD patients were analyzed, in a cross-sectional study design, for demographics, transplant-related history, clinical assessments, symptoms, function, quality-of-life, laboratory values and survival in order to determine their associations with nutritional status. Most patients had long-standing, moderate or severe cGVHD and had failed many lines of therapy. Twenty-nine percent (60/210) of subjects were malnourished, using the subjective Patient-Generated Subjective Global Assessment (PG-SGA) questionnaire and evaluation. No demographic or transplant characteristics were associated with malnutrition; cGVHD of the lungs, gastrointestinal (GI) tract and mouth, NIH global score, cGVHD symptoms, worse functioning, low albumin, poorer survival and low BMI were associated with malnutrition. A predictive model was developed from all variables of significance: cGVHD of the lungs, GI tract, mouth and BMI accurately predicted 84.2% of malnourished patients as well as 87.2% of well-nourished patients. The PG-SGA questionnaire may be a useful tool in diagnosing nutritional deficits in cGVHD patients undergoing one-time evaluations. Longitudinal prospective studies should assess the utility of nutritional support interventions in cGVHD.

Oil-in-water microemulsions stabilized by charged diblock copolymers.

We present here oil-in-water microemulsions stabilized by charged diblock copolymers alone, along with their structural characterization by small-angle neutron scattering measurements. They consist of swollen spherical micelles containing small amounts of oil in their core, which is surrounded by a corona of stretched polyelectrolyte chains. Structural changes, including core size variations, are evidenced when using a cosurfactant, or upon addition of salt, through a contraction of the charged corona. Attempts to relate the micellar structure to the individual copolymer characteristics are also presented, and show that the size of the hydrophobic block mainly determines that of the micelles.

Selection and the competitive standing of health plans in a multiple-choice, multiple-insurer market.

Previous studies have determined that biased selection occurs in multiple-choice, multiple-insurer programs. To the extent that health plans are affected by biased selection, efficiency becomes less important since adverse selection may raise a particular plan's costs relative to those of its competitors. This study finds that both favorable and unfavorable selection deteriorate over time. Thus, not only may selection harm the competitive standing of individual plans, but it may also force these plans to withdraw from the market. With free entry, no plan is immune from fatal adverse selection.

The development and characterization of a fracture-toughened acrylic for luting total joint arthroplasties.

An autopolymerizing fracture-toughened acrylic lute was developed utilizing a toughened prepolymer and a gel-polymerization method. Samples for mechanical and chemical characterization were molded from this material and from untoughened controls. Mechanical testing showed that the mode I fracture toughness (K(IC)) of the toughened lute was increased by 163% over that of the untoughened acrylic controls while the compressive strength and modulus were decreased by 36% and 34%, respectively. The flexural properties of the experimental material were not adversely affected. Analysis of molecular weight and residual monomer data for the experimental and control materials demonstrated that the increase in toughness was due to the presence of the toughened prepolymer. The use of the gel polymerization process gave excellent homogeneity with very low porosity for the experimental polymer, but it resulted in a significant increase in the residual monomer concentration due to the absence of a dispersed phase of prepolymer remnants. This raises questions concerning tissue response to the experimental system.

Thickness and density profiles of polyelectrolyte brushes: dependence on grafting density and salt concentration.

We have performed neutron reflectivity measurements on a monolayer of charged diblock copolymers in a Langmuir trough, and determined precise density profiles of the polyelectrolyte brush at different densities. We obtain profiles in good agreement with existing self-consistent field computations, both for the osmotic and the salted brush regime. We show that the osmotic brush's thickness increases with density.

Spherical polyelectrolyte block copolymer micelles: structural change in presence of monovalent salt.

Spherical polyelectrolyte block copolymer micelles were investigated as a function of added NaCl salt concentration using Small-Angle Neutron Scattering (SANS) and Light Scattering (LS). The micelles are formed by the self-association of charged-neutral copolymers made of a long deuterated polyelectrolyte moiety (NaPSS(d))251 and a short hydrophobic moiety (PEP)52. In presence of salt, the core shape and the aggregation number of the micelles are not affected. The hydrodynamic radius of the micelle is found to be identical to the radius of the whole micelle deduced from neutron scattering and thus the hydrodynamic radius is a valid measure of the corona thickness. At the lowest salt concentrations investigated the thickness of the corona, R(s), remains essentially constant and a contraction is observed above an added-salt concentration c(s) of 2 x 10(-2) M where this crossover concentration corresponds to the average ionic strength of the free counterions in the corona. The contraction takes place while maintaining a rod-like behavior of the chains at short scale and obeys to: R(s) approximately c(s)(-0.18). The exponent 0.18 suggests an electrostatic persistence length proportional to the Debye screening length.

Interleukin 1 alpha mediates collagenase synthesis stimulated by phorbol 12-myristate 13-acetate.

Stimulation of collagenase expression in cultures of normal diploid fibroblasts by the tumor promotor phorbol 12-myristate 13-acetate (PMA) occurs secondarily to synthesis of unknown intermediary proteins. We have investigated the hypothesis that a form of the cytokine interleukin 1 (IL-1) is one intermediate controlling PMA-stimulated collagenase expression. Treatment with an IL-1 receptor antagonist inhibits the constitutive synthesis of collagenase in early passage fibroblast cultures from rabbit. Radioimmunoassay demonstrates that, of the two known IL-1 forms, IL-1 alpha and IL-1 beta, only IL-1 alpha is synthesized and released into the medium of corneal fibroblast cultures. PMA treatment of cells increases the level of IL-1 alpha mRNA; this occurs prior to the increase in collagenase mRNA and corresponds with increased synthesis and release of IL-1 alpha protein. Neutralizing antiserum to IL-1 alpha inhibits constitutive collagenase synthesis. Reagents that inhibit the activity of IL-1 alpha (IL-1 receptor antagonist or neutralizing antibody) also inhibit the PMA-mediated stimulation of collagenase synthesis. These results indicate that constitutive and PMA-stimulated expression of collagenase is regulated through an IL-1 alpha intermediate. In vivo, regulation of the lytic phase of tissue remodeling through the IL-1 alpha intermediate may ensure the recruitment of cells adjacent to the one that received the initial stimulus.

Characterization of poly(L-lactide)-block-poly(ethylene oxide)-block-poly(L-lactide) triblock copolymer by liquid chromatography at the critical condition and by MALDI-TOF mass spectrometry.

Poly(L-lactide)-block-poly(ethylene oxide)-block-poly(L-lactide) triblock copolymers (PLLA-b-PEO-b-PLLA) were fractionated in terms of the number of LLA units by liquid chromatography at the critical condition (LCCC) of PEO block. The fractionated samples were identified using MALDI-TOF mass spectrometry. The dependence of the LCCC retention of the diblock and triblock copolymers on the degree of polymerization of PLLA block(s) follows Martin's rule very well. Unlike the case of PEO-b-PLLA diblock copolymer reported earlier (Lee, H.; et al. Macromolecules 1999, 32, 4143), however, a splitting of the elution peaks containing the same number of LLA units was found. The peak splitting was ascribed to the different length distributions of PLLA blocks at the two ends of the PEO block. From the relative intensities of the peaks, the split peaks were assigned to different isomeric structures of the PLLA blocks. From these results we conclude that the interaction of the triblock copolymers with the stationary phase is affected by the distribution of the interacting blocks at the two ends of the center PEO block, in addition to the total number of LLA units in the triblock copolymer.