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1.  Differences in Health Care Access and Utilization Between Adolescents and Young Adults With Asthma 
Pediatrics  2013;131(5):892-901.
OBJECTIVE:
Studies suggest that young adults have worse health care access, use less primary care, and visit emergency departments more frequently than adolescents. We examined whether these differences existed between older adolescents and young adults with asthma.
METHODS:
Using nationally representative data from the 1999 to 2009 Medical Expenditure Panel Survey, we performed cross-sectional comparisons of access and utilization between older adolescents (ages 14–17) and young adults (ages 19–25) with asthma. In longitudinal analyses, we assessed whether changes in health insurance coverage, schooling, and adult presence at home predicted changes in access and utilization.
RESULTS:
Young adults with asthma were less likely to have a usual source of care (–13.7 percentage points; P < .001) or primary care visit within the past year (–13.9 percentage points; P = .006). They were less likely to fill a short-acting beta-agonist prescription (–10.6 percentage points; P = .02) and more likely to visit the emergency department within the past year (+9.7 percentage points; P = .01). Adjusting for differences in insurance coverage reduced differences in usual source of care and primary care use by 32.4% to 38.0% but reduced the difference in emergency department use by only 10.3%. Among participants aged 16 to 19 in the first survey year, becoming uninsured strongly predicted losing a usual source of care (change relative to no coverage loss: –25.2 percentage points; P = .003).
CONCLUSIONS:
Compared with older adolescents with asthma, young adults with asthma have worse health care access and may use care less optimally. These differences were associated with but were not completely explained by differences in insurance coverage.
doi:10.1542/peds.2012-2881
PMCID: PMC4074656  PMID: 23610211
adolescents; asthma; health care utilization; health insurance; young adult
2.  Binding of HIV-1 gp120 to DC-SIGN Promotes ASK-1-Dependent Activation-Induced Apoptosis of Human Dendritic Cells 
PLoS Pathogens  2013;9(1):e1003100.
During disease progression to AIDS, HIV-1 infected individuals become increasingly immunosuppressed and susceptible to opportunistic infections. It has also been demonstrated that multiple subsets of dendritic cells (DC), including DC-SIGN(+) cells, become significantly depleted in the blood and lymphoid tissues of AIDS patients, which may contribute to the failure in initiating effective host immune responses. The mechanism for DC depletion, however, is unclear. It is also known that vast quantities of viral envelope protein gp120 are shed from maturing HIV-1 virions and form circulating immune complexes in the serum of HIV-1-infected individuals, but the pathological role of gp120 in HIV-1 pathogenesis remains elusive. Here we describe a previously unrecognized mechanism of DC death in chronic HIV-1 infection, in which ligation of DC-SIGN by gp120 sensitizes DC to undergo accelerated apoptosis in response to a variety of activation stimuli. The cultured monocyte-derived DC and also freshly-isolated DC-SIGN(+) blood DC that were exposed to either cross-linked recombinant gp120 or immune-complex gp120 in HIV(+) serum underwent considerable apoptosis after CD40 ligation or exposure to bacterial lipopolysaccharide (LPS) or pro-inflammatory cytokines such as TNFα and IL-1β. Furthermore, circulating DC-SIGN(+) DC that were isolated directly from HIV-1(+) individuals had actually been pre-sensitized by serum gp120 for activation-induced exorbitant apoptosis. In all cases the DC apoptosis was substantially inhibited by DC-SIGN blockade. Finally, we showed that accelerated DC apoptosis was a direct consequence of excessive activation of the pro-apoptotic molecule ASK-1 and transfection of siRNA against ASK-1 significantly prevented the activation-induced excessive DC death. Our study discloses a previously unknown mechanism of immune modulation by envelope protein gp120, provides new insights into HIV immunopathogenesis, and suggests potential therapeutic approaches to prevent DC depletion in chronic HIV infection.
Author Summary
HIV-1 infected individuals become increasingly immunocompromised and susceptible to opportunistic infection during disease progression, which is associated with significant reduction of the dendritic cell number in the peripheral blood or secondary lymphoid tissues. Because dendritic cells are the most powerful antigen-presenting cells, their survival is critical for host defence and inadequate dendritic cell number will fail to induce effective host immune responses. Here we describe a mechanism that may at least partly explain why dendritic cells become significantly depleted in chronic HIV-1 infection. We found that after binding of the HIV-1 envelope protein gp120 to the dendritic cell surface protein DC-SIGN, the subsequent activation by CD40 ligation, or by exposure to bacterial product lipopolysaccharide or pro-inflammatory cytokines such as TNF-α and IL-1β, will lead to overexpression of pro-apoptotic molecule ASK-1, resulting in excessive dendritic cell death. We also confirmed that DC-SIGN(+) dendritic cells in the blood of HIV-1 infected individuals have actually been pre-sensitized by viral gp120, which exists in vast amount in the blood, for activation-induced exorbitant death. Our study thus reveals a previously unknown pathway for dendritic cell depletion and provides clues for potential therapeutic approaches to prevent DC depletion in chronic HIV infection.
doi:10.1371/journal.ppat.1003100
PMCID: PMC3561151  PMID: 23382671
3.  Two-year quality of life after free flap reconstruction in tumor-site discrepancy among Taiwanese with moderately advanced oral squamous cell carcinoma 
Background
This study describes 2-year impact on quality of life (QOL) in relation to the anatomical discrepancy among T4a oral cancer patients after free flap reconstruction in Taiwan.
Methods
Thirty-two patients who underwent tumor ablation with simultaneous microvascular free flap transfer at 2-year follow-up were recruited. They were divided into six subgroups, according to the resected area, consisting of: (1) buccal/retromolar trigone; (2) cheek; (3) commissure; (4) lip; (5) mandible; and (6) tongue. Functional disturbances and daily activity were analyzed using the Version-1 UW QOL Questionnaire with one more specific category: ‘Drooling’. Kruskal-Wallis rank sums analysis was used to test differences in average QOL scores between these subgroups. Post-hoc analysis was applied to assess influence of dominant categories between subgroups.
Results
The category ‘Pain’ revealed the highest average score and reached significant statistical difference (P = 0.019) among all the categories, however, the category ‘Employment’ averaged the lowest score. Regarding ‘Pain’, there existed a statistical significance (P = 0.0032) between the commissure- and cheek-involved groups, which described the former showed poorer pain quality of life.
Conclusions
The commissure-involved group had the lowest average score, which might imply the worst QOL in our study, especially for the categories ‘Pain’ and ‘Drooling’. This present study of T4a patients was the first carried out in Taiwan implementing the QOL questionnaire, and its results may serve for future reference.
doi:10.1186/1477-7819-10-145
PMCID: PMC3412696  PMID: 22789070
Quality of life; T4a oral cancer; Free flap transfer; Questionnaire; Taiwanese
4.  Volumetric Interpretation of Protein Adsorption: Interfacial Packing of Protein Adsorbed to Hydrophobic Surfaces from Surface-Saturating Solution Concentrations 
Biomaterials  2010;32(4):969-978.
The maximum capacity of a hydrophobic adsorbent is interpreted in terms of square or hexagonal (cubic and face-centered-cubic, FCC) interfacial packing models of adsorbed blood proteins in a way that accommodates experimental measurements by the solution-depletion method and quartz-crystal-microbalance (QCM) for the human proteins serum albumin (HSA, 66 kDa), immunoglobulin G (IgG, 160 kDa), fibrinogen (Fib, 341 kDa), and immunoglobulin M (IgM, 1000 kDa). A simple analysis shows that adsorbent capacity is capped by a fixed mass/volume (e.g. mg/mL) surface-region (interphase) concentration and not molar concentration. Nearly analytical agreement between the packing models and experiment suggests that, at surface saturation, above-mentioned proteins assemble within the interphase in a manner that approximates a well-ordered array. HSA saturates a hydrophobic adsorbent with the equivalent of a single square-or-hexagonally-packed layer of hydrated molecules whereas the larger proteins occupy two-or-more layers, depending on the specific protein under consideration and analytical method used to measure adsorbate mass (solution depletion or QCM). Square-or-hexagonal (cubic and FCC) packing models cannot be clearly distinguished by comparison to experimental data. QCM measurement of adsorbent capacity is shown to be significantly different than that measured by solution depletion for similar hydrophobic adsorbents. The underlying reason is traced to the fact that QCM measures contribution of both core protein, water of hydration, and interphase water whereas solution depletion measures only the contribution of core protein. It is further shown that thickness of the interphase directly measured by QCM systematically exceeds that inferred from solution-depletion measurements, presumably because the static model used to interpret solution depletion does not accurately capture the complexities of the viscoelastic interfacial environment probed by QCM.
doi:10.1016/j.biomaterials.2010.09.075
PMCID: PMC3040988  PMID: 21035180
Protein adsorption; solution depletion; quartz crystal microbalance; interphase
5.  X-ray spectroscopy characterization of self-assembled monolayers of nitrile-substituted oligo(phenylene ethynylene)s with variable chain length 
Summary
Self-assembled monolayers (SAMs) of nitrile-substituted oligo(phenylene ethynylene) thiols (NC-OPEn) with a variable chain length n (n ranging from one to three structural units) on Au(111) were studied by synchrotron-based high-resolution X-ray photoelectron spectroscopy and near-edge absorption fine-structure spectroscopy. The experimental data suggest that the NC-OPEn molecules form well-defined SAMs on Au(111), with all the molecules bound to the substrate through the gold–thiolate anchor and the nitrile tail groups located at the SAM–ambient interface. The packing density in these SAMs was found to be close to that of alkanethiolate monolayers on Au(111), independent of the chain length. Similar behavior was found for the molecular inclination, with an average tilt angle of ~33–36° for all the target systems. In contrast, the average twist of the OPEn backbone (planar conformation) was found to depend on the molecular length, being close to 45° for the films comprising the short OPE chains and ~53.5° for the long chains. Analysis of the data suggests that the attachment of the nitrile moiety, which served as a spectroscopic marker group, to the OPEn backbone did not significantly affect the molecular orientation in the SAMs.
doi:10.3762/bjnano.3.2
PMCID: PMC3304316  PMID: 22428092
nitrile substitution; oligo(phenylene ethynylene); self-assembled monolayers; twist angle; X-ray absorption spectroscopy

Results 1-5 (5)