Programmed Sequential Additions to Halogenated Mucononitriles.

Dihalomucononitriles were synthesized and their reactivity evaluated to assess their ability to function as linchpin reagents. Bis(2-chloroacrylonitrile) and bis(2-bromoacrylonitrile) were synthesized from 2,1,3-benzothiadiazole and undergo conjugate addition/elimination reactions with both nitrogen (40-95% yield) and carbon nucleophiles (72-93% yield). Secondary amines undergo monosubstitutions, while carbon nucleophiles are added twice. The sequence of addition of the nucleophiles could be controlled to give mixed addition products. The multicomponent coupling products could then be converted to natural product like motifs using intramolecular cyclization reactions.

Enantioselective Construction of Quaternary Stereogenic Centers by the Addition of an Acyl Anion Equivalent to 1,3-Dienes.

We report the enantioselective formation of quaternary stereogenic centers by the intermolecular addition of malononitrile, an acyl anion equivalent, and related pronucleophiles to several 1,3-disubstituted acyclic 1,3-dienes in the presence of a Pd-PHOX catalyst. Products are obtained in up to 88% yield and 99:1 er and in most cases are formed as a single regioisomer. The products' malononitrile unit undergoes oxidative functionalization to afford ß,γ-unsaturated carbonyls bearing internal olefins and α-quaternary stereogenic centers.

Critical Contact Lens Oxygen Transmissibility and Tear Lens Oxygen Tension to Preclude Corneal Neovascularization.

OBJECTIVE: The purpose of this study is to determine the peripheral oxygen transmissibility (pDk/t) and respective central oxygen transmissibility (cDk/t) in soft contact lenses (SCLs) which might preclude SCL-driven corneal neovascularization (NV) in healthy myopic SCL users. METHODS: Twenty subjectively successful SCL-wearing patients who presented with asymptomatic but active peripheral corneal NV (not ghost vessels) were recruited as study patients. Twenty-one patients who did not have NV were similarly recruited as controls. Demographic data were collected. Corneal NV was documented and photographed. Current habitual SCLs were collected and thicknesses measured to allow for the calculation of both pDk/t and cDk/t and estimation of local tear oxygen tensions. RESULTS: No statistical differences between study and control groups in patient age, refraction, or the numbers of years, days per week, or hours per day patients reported SCL wear were identified. Statistically significant differences were found between the two groups for both pDk/t (P=0.006) and cDk/t (P=0.004): mean (±SD) pDk/t was 38.0±23.5 and 19.2±17.7 Fatt units for control and study corneas, respectively. Mean cDk/t were 80.0±54.4 and 36.8±33.1 Fatt units for control and study corneas, respectively. Peripheral tear oxygen tension that "protected" corneas from vascular filling was over 84 mm Hg. CONCLUSION: Maintaining a pDk/t above 30 to 40 Fatt units with daily wear SCLs should protect most normal corneas from NV as a complication of SCL wear.

Determinants and standardization of mesopic visual acuity.

PURPOSE: It is well established that visual acuity (VA) decreases with luminance but the specific factors that are responsible remain unclear. The purpose of this study was to quantify the contributions of accommodative error, pupil size, and higher-order aberrations to the decrease in VA when transitioning from photopic to mesopic light levels. Additionally, repeatability of VA at photopic and mesopic levels was measured to derive a luminance recommendation for mesopic VA testing, which can provide the standardization needed for future translational clinical studies and the widespread adoption of mesopic VA testing. METHODS: Monocular VAs were assessed at one photopic and three mesopic light levels: 94, 3, 0.75, and 0.38 cd/m, with an E-ETDRS testing system in 43 normal subjects. Accommodative error, pupil size, and higher-order aberrations were obtained. Twenty subjects were retested at another visit to assess VA repeatability. RESULTS: The mean (±SD) logMAR (logarithm of the minimum angle of resolution) VA was -0.08 (±0.06) at 94 cd/m, 0.05 (±0.07) at 3 cd/m, 0.16 (±0.06) at 0.75 cd/m, and 0.27 (±0.09) at 0.38 cd/m. Light level and accommodative error were significantly associated with VA, and light level explained 75% of the variance. The mean differences in VAs between two visits were not significantly different from zero (p > 0.05). The coefficients of repeatability for 94, 3, 0.75, and 0.38 cd/m were 0.08, 0.11, 0.14, and 0.14 logMAR, respectively. CONCLUSIONS: Light level, among all other factors studied, contributes the most to the reduction in VA tested under mesopic conditions. Testing mesopic VA at 0.75 cd/m, or about 2.0 log units less than photopic testing, provides a significant and repeatable decrease in VA similar to standardized low-contrast VA testing, and therefore this level is recommended.

Evaluation of the Waggoner Computerized Color Vision Test.

PURPOSE: Clinical color vision evaluation has been based primarily on the same set of tests for the past several decades. Recently, computer-based color vision tests have been devised, and these have several advantages but are still not widely used. In this study, we evaluated the Waggoner Computerized Color Vision Test (CCVT), which was developed for widespread use with common computer systems. METHODS: A sample of subjects with (n = 59) and without (n = 361) color vision deficiency (CVD) were tested on the CCVT, the anomaloscope, the Richmond HRR (Hardy-Rand-Rittler) (4th edition), and the Ishihara test. The CCVT was administered in two ways: (1) on a computer monitor using its default settings and (2) on one standardized to a correlated color temperature (CCT) of 6500 K. Twenty-four subjects with CVD performed the CCVT both ways. Sensitivity, specificity, and correct classification rates were determined. RESULTS: The screening performance of the CCVT was good (95% sensitivity, 100% specificity). The CCVT classified subjects as deutan or protan in agreement with anomaloscopy 89% of the time. It generally classified subjects as having a more severe defect compared with other tests. Results from 18 of the 24 subjects with CVD tested under both default and calibrated CCT conditions were the same, whereas the results from 6 subjects had better agreement with other test results when the CCT was set. CONCLUSIONS: The Waggoner CCVT is an adequate color vision screening test with several advantages and appears to provide a fairly accurate diagnosis of deficiency type. Used in conjunction with other color vision tests, it may be a useful addition to a color vision test battery.

Evaluation of serum biomarkers IL-17 and CTX for BRONJ: a pilot clinical case-control study.

A serious complication of bisphosphonate (BP) therapy is BP-related osteonecrosis of the jaw (BRONJ). Currently, no biomarkers exist to identify patients at risk. We evaluated whether interleukin-17 and C-telopeptide correlate with BRONJ development. We conducted a case-control study using patients with a history of BP therapy. Quantitative enzyme-linked immunosorbent assay and Student's t-test were done. Both markers were significantly higher in BRONJ, suggesting altered immune responses and bone remodeling may play roles in BRONJ development.

Allergic conjunctivitis and dry eye syndrome.

BACKGROUND: Allergic conjunctivitis (AC) and dry eye syndrome (DES) are 2 of the most common anterior inflammatory disorders of the ocular surface and one does not preclude the coexistence of the other. OBJECTIVES: To examine the potential overlap between AC and DES as comorbidities. METHODS: Using the validated questionnaire known as Subjective Evaluation of Symptom of Dryness, we studied self-reported itchiness, dryness, and redness. In an outpatient optometric setting, 689 patients treated from January 1, 2007, to January 1, 2011, were surveyed for their ocular history and categorized according to their reported level of discomfort of itchiness, dryness, and redness. RESULTS: Patients ranged in age from 5 to 90 years (median age, 25 years; 39.5% male; 60.5% female). In the studied 689 patients, clinically significant itchiness was found in 194 (28.2%), dry eyes in 247 (35.8%), and redness in 194 (28.2%). Symptom overlap was demonstrated in many of the patients. Of the 194 patients with itchiness, 112 (57.7%) had clinically significant dryness. In the 247 patients with dry eyes, 112 (45.3%) had clinically significant itch. Redness was apparent in 120 of the 194 patients with itch (61.9%) and 122 of the 247 patients with dryness (49.4%). Statistical analysis demonstrated that self-reported itchiness, dryness, and redness were not independent of each other (P<.001; Pearson χ(2) test). The odds of patients with "itchy eyes" also experiencing dry eyes were 2.11 times and the odds of these patients also experiencing redness were 7.34 times that of patients with nonitchy eyes. CONCLUSIONS: Most patients with "itchy eyes" consistent with AC also have dry eyes and redness. These results suggest that some symptomatic patients concomitantly have features of AC and DES.

Three-dimensional spheroid culture of human gingiva-derived mesenchymal stem cells enhances mitigation of chemotherapy-induced oral mucositis.

Mesenchymal stem cells (MSCs) are capable of regenerative and immunomodulatory functions in cell-based therapies in a variety of human diseases and injuries; however, their therapeutic efficacy and potential side effects remain major obstacles in clinical applications. We report here a 3D spheroid culture approach to optimize stem cell properties and therapeutic effects of human gingiva-derived mesenchymal stem cells (GMSCs) in mitigation of experimental oral mucositis. Under growth condition of ultra-low attachment, GMSCs spontaneously aggregated into 3D spheroids and exhibited distinct early stem cell phenotype characterized by elevated expression Stro-1 and CXC chemokine receptor 4 (CXCR-4) as well as OCT-4 and Nanog, 2 important transcriptional factors relevant to stem cell properties, and decreased expression of MSC-associated markers, including CD29, CD90, and CD105. Functionally, spheroid GMSCs are capable of enhanced multipotency and augmented secretion of several chemokines and cytokines relevant to cell migration, survival, and angiogenesis. More importantly, spheroid GMSCs expressed increased levels of reactive oxygen species, hypoxia-inducible factor (HIF)-1 and -2α, and manganese superoxide dismutase, which correlated with improved resistance to oxidative stress-induced apoptosis. Using an in vivo murine model of chemotherapy-induced oral mucositis, we demonstrated that spheroid-derived GMSCs possessed better therapeutic efficacy than their adherent cells in reversing body weight loss and promoting the regeneration of disrupted epithelial lining of the mucositic tongues. These findings suggest that 3D spheroid culture allows early stemness preservation and potentially precondition GMSCs for enhanced mitigation of oral mucositis.

Human gingiva-derived mesenchymal stromal cells attenuate contact hypersensitivity via prostaglandin E2-dependent mechanisms.

The immunomodulatory and anti-inflammatory functions of mesenchymal stromal cells (MSCs) have been demonstrated in several autoimmune/inflammatory disease models, but their contribution to the mitigation of contact hypersensitivity (CHS) remains unclear. Here, we report a new immunological approach using human gingiva-derived MSCs (GMSCs) to desensitize and suppress CHS and the underlying mechanisms. Our results showed that systemic infusion of GMSCs before the sensitization and challenge phase dramatically suppress CHS, manifested as a decreased infiltration of dendritic cells (DCs), CD8(+) T cells, T(H)-17 and mast cells (MCs), a suppression of a variety of inflammatory cytokines, and a reciprocal increased infiltration of regulatory T cells and expression of IL-10 at the regional lymph nodes and the allergic contact areas. The GMSC-mediated immunosuppressive effects and mitigation of CHS were significantly abrogated on pretreatment with indomethacin, an inhibitor of cyclooxygenases. Under coculture condition of direct cell-cell contact or via transwell system, GMSCs were capable of direct suppression of differentiation of DCs and phorbol 12-myristate 13-acetate-stimulated activation of MCs, whereas the inhibitory effects were attenuated by indomethacin. Mechanistically, GMSC-induced blockage of de novo synthesis of proinflammatory cytokines by MCs is mediated partly by the tumor necrosis factor-alpha/prostaglandin E(2) (PGE(2)) feedback axis. These results demonstrate that GMSCs are capable of desensitizing allergic contact dermatitis via PGE(2)-dependent mechanisms.

Human gingiva-derived mesenchymal stem cells elicit polarization of m2 macrophages and enhance cutaneous wound healing.

Increasing evidence has supported the important role of mesenchymal stem cells (MSCs) in wound healing, however, the underlying mechanism remains unclear. Recently, we have isolated a unique population of MSCs from human gingiva (GMSCs) with similar stem cell-like properties, immunosuppressive, and anti-inflammatory functions as human bone marrow-derived MSCs (BMSCs). We describe here the interplay between GMSCs and macrophages and the potential relevance in skin wound healing. When cocultured with GMSCs, macrophages acquired an anti-inflammatory M2 phenotype characterized by an increased expression of mannose receptor (MR; CD206) and secretory cytokines interleukin (IL)-10 and IL-6, a suppressed production of tumor necrosis factor (TNF)-α, and decreased ability to induce Th-17 cell expansion. In vivo, we demonstrated that systemically infused GMSCs could home to the wound site in a tight spatial interaction with host macrophages, promoted them toward M2 polarization, and significantly enhanced wound repair. Mechanistically, GMSC treatment mitigated local inflammation mediated by a suppressed infiltration of inflammatory cells and production of IL-6 and TNF-α, and an increased expression of IL-10. The GMSC-induced suppression of TNF-α secretion by macrophages appears to correlate with impaired activation of NFκB p50. These findings provide first evidence that GMSCs are capable to elicit M2 polarization of macrophages, which might contribute to a marked acceleration of wound healing.

Preoperative assessment of corneal and refractive stability in soft contact lens wearing photorefractive candidates.

PURPOSE: This pilot study compared traditional methodologies; manifest refraction and keratometry, with that of newer technologies; corneal topography, and optical pachymetry, in assessing corneal and refractive stabilization after soft contact lens wear in photorefractive candidates. The timeline differences among these various technologies in determining refractive and corneal stability were investigated. METHODS: This was a masked prospective observational clinical study of full-time soft contact lens subjects on various wear schedules, all eligible candidates for photorefractive surgery. Subjects discontinued contact lens wear within 30 min of the initial study visit. During each study visit, the same sequence of tests were performed (manifest refraction, keratometry, corneal topography, and optical pachymetry). The timing of the last visit was determined when the four procedures resulted in stable findings when compared with the previous visit. RESULTS: Fifteen soft contact lens wearers and five noncontact lens wearing controls completed the study. The mean number of days until stability of the 15 test subjects were: 10.7 +/- 10.4 days with manifest refraction, 16.2 +/- 17.5 days with keratometry, 28.1 +/- 17.7 days with topography, and 35.1 +/- 20.8 days with pachymetry. Within the control group, intraclass correlation coefficients for all four methods were > or =0.89, indicating very little variability. Analysis with the randomized block design found statistical differences between traditional and newer technologies in their assessment of stability (p < 0.001). One-way Analysis of variance of the various soft contact lenses modalities suggested extended hydrogel wearers taking the longest time to reach stability after discontinuing full-time contact lens use. CONCLUSIONS: Corneal curvature and thickness measurements took the longest to achieve consistency. Thus, topography and pachymetry may be better methods to determine ocular stability before photorefractive surgery. In light of this finding, the current protocol in practice of determining the readiness of contact lens candidates for photorefractive surgery may be inadequate.

Accommodative insufficiency is the primary source of symptoms in children diagnosed with convergence insufficiency.

PURPOSE: Accommodative insufficiency (AI) and convergence insufficiency (CI) have been associated with similar symptomology and frequently present at the same time. The severity of symptomology in CI has been linked to the severity of the CI, suggesting a dose-dependent relationship. However, with increasing severity of CI also comes increased comorbidity of AI. AI alone has been shown to cause significant symptomology. We hypothesize that AI drives the symptoms in CI with a comorbid AI condition (CIwAI) and that it is the increased coincidence of AI, rather than increased severity of CI, which causes additional symptomology. METHODS: Elementary school children (n = 299) participated in a vision screening that included tests for CI and AI and the CISS-V15 symptom survey. They were categorized into four groups:1) normal binocular vision (NBV); 2) AI-only; 3) CI-only; and 4) CIwAI. One hundred seventy elementary school children fell into the categories of interest. RESULTS: Pairwise comparison of the group means on the symptom survey showed: 1) children with AI-only (mean = 19.7, p = 0.006) and children with CIwAI (mean = 22.8, p = 0.001) had significantly higher symptom scores than children with NBV (mean = 10.3); and 2) children with CI-only (mean = 12.9, p = 0.54) had a similar symptom score to children with NBV. Using a two-factor analysis of variance (AI and CI), the AI effect was significant (AI mean = 21.56; no AI mean = 11.56, p < 0.001), whereas neither the CI effect (p = 0.16) nor the CI by AI interaction effect (p = 0.66) were significant. CONCLUSION: CI is a separate and unique clinical condition and can occur without a comorbid AI condition, our CI-only group. Past reports of high symptom scores for children with CI are the result of the presence of AI, a common comorbid condition. When AI is factored out, and children with CI only are evaluated, they are not significantly more symptomatic than children with NBV.

Elevated vascular endothelial growth factor in keloids: relevance to tissue fibrosis.

Excessive scar or keloid shares common features of a benign dermal growth. Yet, in contrast to malignant tumor, a keloid does not expand beyond the dermis. What triggers the continuing growth of a benign lesion? Deficient or overabundant levels of vascular endothelial growth factor have been reported to contribute to impaired or excessive wound healing. Although numerous studies have examined the pathophysiology of impaired wounds, little information has been provided on mechanisms of exuberant healing. The molecular basis of keloid formation is governed by the interplay of cellular signaling pathways, specific target gene activation, and the nature of the microenvironment. Recent works have demonstrated an accumulation of hypoxia-inducible factor-1alpha protein in freshly biopsied keloid tissues, thus providing first evidence that a local state of hypoxia exists in keloids. Our findings and the findings of others support at least two plausible mechanisms implicated in the development of fibrotic wounds, a state of ongoing fibroplasia or inflammation and an excessive accumulation of extracellular matrix. This article will review recent works examining the potential role of vascular endothelial growth factor in keloid pathogenesis with particular focus on its involvement in the two proposed pathological processes, a prolonged inflammation and an altered balance in extracellular matrix metabolism.