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Open Access Publications from the University of California

Scholarly Works (96 results)

  • Article
  • Peer Reviewed
UCLA Previously Published Works (2015)
    Cover page: Methadone treatment in primary care
    • Peer Reviewed
    UC San Diego Previously Published Works (2021)
      Cover page: Laser Ultrasonic Imaging of Wavefield Spatial Gradients for Damage Detection
      • Article
      • Peer Reviewed
      California Breast Cancer Research Program Funded Publications (1997)
        Cover page: Molecular cloning and characterization of human JNKK2, a novel Jun NH2-terminal kinase-specific kinase
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        • Peer Reviewed
        UC Riverside Previously Published Works (2000)

        This study was carried out to determine if the bronchoconstrictive effect of cigarette smoke (CS) is enhanced when airway hyperresponsiveness is induced by ovalbumin (Ova) sensitization, and if so, whether an increase in endogenously released tachykinins is involved. The bronchoconstrictive effects of an acute CS inhalation challenge (15 ml; 50% concentration) were compared between guinea pigs sensitized with aerosolized Ova and matching control animals (receiving saline aerosol). In Ova-sensitized animals, there were marked increases in the numbers of eosinophils and neutrophils in the bronchoalveolar lavage fluid (BALF), which was accompanied by an elevated bronchomotor response to acetylcholine (ACh). The baseline lung resistance (RL) and dynamic pulmonary compliance (Cdyn) were not significantly different between the two groups; however, the same CS inhalation challenge evoked a significantly more intense bronchoconstriction in the Ova-sensitized group (control group: DeltaRL = 68 +/- 8%, DeltaCdyn = -26 +/- 6%; Ova group: DeltaRL = 425 +/- 76%; DeltaCdyn = -47 +/- 8%). The levels of substance P-like immunoreactivity (SP-LI) and calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) measured in the bronchoalveolar lavage (BAL) collected after CS inhalation challenge were also significantly greater in Ova-sensitized animals than in control animals. Furthermore, pretreatment with SR-48968, a selective antagonist of neurokinin-2 (NK(2)) receptor, inhibited more than 85% of the enhanced bronchomotor responses to CS challenge, but did not significantly reduce the airway hyperresponsiveness to ACh in Ova-sensitized guinea pigs. These results show that Ova sensitization induces airway hyperresponsiveness to inhaled CS, and that the endogenous tachykinins evoked by CS-induced activation of lung C fibers play a primary role in this augmented response.

          • Article
          • Peer Reviewed
          UC San Diego Previously Published Works (2015)
          Purpose To evaluate long-term, longitudinal displacement of the optic nerve head (ONH) and anterior lamina cribrosa surfaces in glaucoma patients imaged with spectral-domain optical coherence tomography (SD OCT). Design Prospective study. Participants A total of 173 eyes of 108 subjects (88 with glaucoma and 20 normal subjects) followed for a mean of 5.3 years. Methods The optic disc was imaged with SD OCT at approximately 4-month intervals, and the ONH surface depth (ONHSD), anterior lamina cribrosa surface depth (ALCSD), and prelaminar tissue thickness (PTT) were measured. The reproducibility coefficients of ONHSD, ALCSD, and PTT were calculated from 2 baseline measurements of the glaucoma group. Change in ONHSD/ALCSD/PTT was confirmed when the differences between the first baseline and the latest 2 consecutive follow-up visits were greater than the corresponding reproducibility coefficient. Factors associated with ONHSD and ALCSD changes were identified with linear mixed modeling. Main Outcome Measures Proportion of eyes with ONHSD/ALCSD change. Results Within the glaucoma group, 23.9% (33 eyes) had confirmed ONHSD change (15.2% with posterior and 8.7% with anterior displacement) and 24.6% (34 eyes) had confirmed ALCSD change (12.3% with posterior and 12.3% with anterior displacement). Some 9.4% (13 eyes) showed a decrease in PTT, and 2.2% (3 eyes) showed an increase in PTT. The specificity for detection of ONHSD/ALCSD/PTT change was 91.4% (95% confidence interval [CI], 77.6-97.0), 82.9% (95% CI, 67.3-91.9), and 94.3% (95% CI, 81.4-98.4), respectively. There were no significant differences in the proportion of eyes with visual field progression or history of filtration surgery between the groups with anterior and posterior displacement of ONH/anterior laminar surfaces (P ≥ 0.678). For each millimeter of mercury increase in the average intraocular pressure (IOP) during follow-up, the ONH and anterior laminar surfaces displaced posteriorly by 1.6 μm and 2.0 μm, respectively. An older age was associated with a decrease in magnitude of posterior displacement of the ONH and anterior laminar surfaces (P ≤ 0.009). Conclusions The ONH and anterior laminar surfaces displaced not only posteriorly but also anteriorly (with reference to Bruch's membrane opening) in a significant portion of glaucoma patients. The magnitude of change was related to age and the averaged IOP during follow-up.
            Cover page: Optic Nerve Head Deformation in Glaucoma: A Prospective Analysis of Optic Nerve Head Surface and Lamina Cribrosa Surface Displacement
            • Article
            • Peer Reviewed
            UCLA Previously Published Works (2015)
            Previous studies suggest that the implementation of universal precaution (UP) plays a role in reducing HIV stigma. In this study we investigate the efficacy of a stigma reduction intervention on UP compliance and explore whether UP compliance could potentially influence HIV stigma reduction in medical settings. A randomized controlled intervention trial was conducted in two provinces of China with 1760 healthcare service providers recruited from 40 county-level hospitals. Longitudinal analyses included data collection at baseline, 6-, and 12-month follow-up assessments. Using a hierarchical modeling approach, we estimated the intervention effect for each provider's UP compliance and its potential mediating role on HIV stigma with the bootstrapping method. A significant intervention effect on UP compliance was observed at both the 6- and 12-month follow-up assessments. The intervention effect on provider avoidance intent was partially mediated by the provider's own UP compliance at the two follow-up points. This study provides evidence that UP compliance should be part of HIV stigma reduction programs, especially in resource-restrained countries. Findings suggest that a protected work environment may be necessary but not sufficient to address HIV stigma in medical settings.
              Cover page: Addressing HIV stigma in protected medical settings
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              • Peer Reviewed
              UC Riverside Previously Published Works (1998)

              Airway hyperreactivity is a hallmark of asthma. Yet, the role of allergic sensitization in the hyperreactivity remains controversial. This study examined the effects of airborne cockroach allergen (CRa) sensitization on the contractility of bronchial (BSM) and tracheal (TSM) smooth muscle rings to cholinergic stimulations, and to specific antigen, in vitro. Guinea pigs were actively immunized with CRa, 5 mg (high dose, HD), 0.5 mg (low dose, LD), or saline aerosols (2x/day, 5 days/week, for 4 weeks) and challenged by CRa inhalation 5 days after last exposure. Twenty-four hours postchallenge, the contractions of the TSM and BSM to electrical field stimulation (EFS), acetylcholine (ACh), and to CRa were measured in vitro. In addition, the contraction to these stimuli were also examined in the passively sensitized TSM with the sera of CRa-immunized guinea pigs. The contractile responses of actively immunized and passively sensitized tissues to EFS and ACh were very similar to those of control tissues. CRa induced dose-dependent contractions in both actively immunized and passively sensitized, but not in control, tissues. The CRa-induced contraction was stronger in the HD group than in the LD group (p<0.0001). Leukotriene C4/D4 receptor antagonist LY-171883 inhibited the CRa-induced contraction by 86% in actively immunized TSM, and by 9% in the passively sensitized TSM. Pyrilamine inhibited the contraction by 57% in actively immunized TSM and 70% in passively sensitized TSM. The results indicate that CRa sensitization does not cause increased airway smooth muscle contractility to cholinergic stimulations, but induces antigen-specific contractions in vitro. Leukotrienes appear to play a significant role in the CRa-specific contractions, more in the actively immunized than those in the passively sensitized tissues, while histamine exerts a moderate effect on the CRa-induced contractions.

                • Article
                • Peer Reviewed
                UCLA Previously Published Works (2014)

                Background and purpose

                Embolization is an important therapeutic technique in brain arteriovenous malformations; however, little has been reported on the factors contributing to complications. We retrospectively reviewed a large series of supratentorial brain AVMs to identify the angioarchitectural characteristics that might be associated with the complications of embolization and poor clinical outcomes.

                Materials and methods

                The clinical and angiographic features of 130 consecutive patients with supratentorial brain AVMs embolized with ethylene-vinyl alcohol copolymer in our hospital from 2005-2008 were retrospectively reviewed. None of these patients had prior embolization. Complications were classified as transient neurologic deficits, persistent neurologic deficits, and death. Univariate and multivariate analyses were conducted to assess the angiographic features in patients with and without complications.

                Results

                Twenty-three complications occurred in 130 embolization procedures, 13 (10%) were transient neurologic deficits (9 ischemic and 4 hemorrhagic), 9 (6.92%) were persistent neurologic deficits (7 ischemic and 2 hemorrhagic), and 1 death occurred. By univariate analyses, eloquent cortex (OR, 2.57; 95% CI, 1.08-3.42) and exclusive deep venous drainage (OR, 4.56; 95% CI, 1.28-9.67) were correlated with procedural complications. The impaction of eloquent cortical location (P = .001) and exclusive deep venous drainage (P = .035) on complications were also demonstrated by multivariate analysis. Eloquent cortex mainly resulted in permanent ischemic neurologic deficit; occlusion of drainage vein was significantly correlated with periprocedural hemorrhage in supratentorial brain AVMs with subtotal and partial embolization.

                Conclusions

                In a retrospective study on supratentorial brain AVMs with first-time embolization, 6.92% of patients had permanent neurologic deficit or death. Eloquent cortical location and exclusive deep venous drainage were associated with complications.
                  Cover page: Angioarchitectural Characteristics Associated with Complications of Embolization in Supratentorial Brain Arteriovenous Malformation
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                  UC Irvine Previously Published Works (2010)
                  The MEGAN model was used to quantify isoprene emission in the Pearl River Delta (PRD) region for 2006. Two sensitive experiments were conducted in order to investigate the impacts of uncertainties in simulated, meteorological, near-surface weather elements on modeled isoprene emission. The results showed that the annual isoprene emission was 95.56 × 106 kg C in the PRD in 2006. Due to variations of meteorological conditions, the isoprene emission displayed a remarkable seasonal and diurnal variation. The highest seasonal emission flux was in summer with a value of 0.920 t · km-2. Considering diurnal patterns, the highest emission rate was at 13:00 local time. The results of sensitive experiments revealed that errors in MM5-simulated meteorological elements significantly impacted isoprene emission while overestimated (underestimated) solar radiation could increase (decrease) the emission rate by 36.20%~50.70% (30.73%~41.88%), which was larger than changes caused by temperature. However, changes in meteorological inputs did not affect the diurnal pattern of isoprene emission, just the emission rate. The emission rate of isoprene changed mostly at 8:00 in the morning or at 17:00 in the afternoon.
                    Cover page: Impacts of errors in meteorological simulations on estimation of isoprene emissionCreative Commons 'BY' version 4.0 license
                    • Article
                    • Peer Reviewed
                    UC Irvine Previously Published Works (2013)
                    This study investigated the impacts of seasonal and regional variability in biogenic volatile organic compounds (BVOCs) on surface ozone over the Pearl River delta (PRD) region in southern China in 2010 with the WRF-Chem/MEGAN (Weather Research and Forecasting coupled with Chemistry/Model of Emissions of Gases and Aerosols from Nature) modeling system. Compared to observations in the literature and this study, MEGAN tends to predict reasonable BVOC emissions in summer, but may overestimate isoprene emissions in autumn, even when the local high-resolution land-cover data and observed emission factors of BVOCs from local plant species are combined to constrain the MEGAN BVOC emissions model. With the standard MEGAN output, it is shown that the impact of BVOC emissions on the surface ozone peak is ∼3 ppb on average with a maximum of 24.8 ppb over the PRD region in autumn, while the impact is ∼10 ppb on average, with a maximum value of 34.0 ppb in summer. The areas where surface ozone is sensitive to BVOC emissions are different in autumn and in summer, which is primarily due to the change of prevailing wind over the PRD; nevertheless, in both autumn and summer, the surface ozone is most sensitive to the BVOC emissions in the urban area because the area is usually VOC-limited. Three additional experiments concerning the sensitivity of surface ozone to MEGAN input variables were also performed to assess the sensitivity of surface ozone to MEGAN drivers, and the results reveal that land cover and emission factors of BVOCs are the most important drivers and have large impacts on the predicted surface ozone. © 2013 Author(s).
                      Cover page: Impacts of seasonal and regional variability in biogenic VOC emissions on surface ozone in the Pearl River delta region, ChinaCreative Commons 'BY' version 4.0 license
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